APPC 2000

PREFACE

PHOTO

COMMITTEES

CONTENTS

Ga₂O₃(Gd₂O₃) as a gate dielectric on GaAs has been shown to possess a low interfacial density of states. The electrical, chemical, and structural properties of this novel oxide and its interface with GaAs are discussed. The interfacial oxide layers on GaAs were found to be a single crystal of pure Gd₂O₃. Various GaAs metal-oxide-semiconductor field-effect-transistors (MOSFETs) and their device performance are reviewed.

The long standing negative (mass)² anomaly encountered in attempts to measure the mass of the electron neutrino may be an indication of physics beyond the standard model. It is demonstrated that an additional charged current interaction which is not of V – A form, and which is at least an order of magnitude weaker than the standard model charged current interaction, will produce a spectrum, which, if fitted by the standard model, may give a negative value for . A possible physical explanation of the time dependent effects seen by the Troitsk experiment is also provided.

The recent studies of the KH₂PO₄ family mixed crystals with long-range ferroelectric (FE) order and short-range glass order have been reviewed. In mixed crystals of KH₂PO₄ family FE or antiferroelectric (AFE) with intermediate mixing concentration, a competing interaction gives rise to a nonergodic proton glass (PG) similar to magnetic spin glass. To understand the phase diagram, we have investigated the phase near FE boundary and observed a coexistence of FE and PG in Rb_1−x(NH₄)_xH₂AsO₄ and Rb_1−x(NH₄)_xH₂PO₄ mixed crystals. The nonergodic behavior of the coexisting PG was investigated by the polarization as well as dielectric constant measurement. The remaining FE polarization and the low freezing temperature were discussed in terms of mean field model of dipole glass systems.

Quantum Zeno Effect (QZE) is the suppression of the inter-subspace transition by a relatively fast intra-subspace decoherence. Earlier, we had proposed a QZE–based mechanism for the temperature-dependent normal-state c-axis resistivity of the layered high-T_c cuprate superconductors in which the single-particle inter-layer tunneling is blocked by the strong intra-layer decoherence (entanglement). We now argue that while the single-particle inter-layer tunneling is thus blocked, the tunneling of the bosonic BCS-like pairs must remain unblocked inasmuch as a BCS pairing condensate is an eigenstate of the pair annihilation operator. This pair tunneling stabilizes high-T_c superconductivity energetically.

Recent years have seen an increased interest in the statistical physics of proteins. While most investigations focus on minimal protein models, we show that the thermodynamics of folding can also be studied for realistic models, when modern simulation techniques such as the generalized-ensemble approach are employed.

We discuss first the properties of unstable nuclei in the framework of the relativistic mean field (RMF) theory. We take the RMF theory as a phenomenological theory with several parameters, whose form is constrained by the successful microscopic theory (RBHF), and whose values are extracted from the experimental data of unstable nuclei. We find the outcome with the use of the parameter sets (TM1 and TMA) is promising in comparison with various experimental data on finite nuclei including unstable ones. We construct then the equation of state of nuclear matter for the use of supernova. We present also the simulations of supernova with the newly calculated equation of state in the prompt explosion scenario.

No abstract received.

A new kind of optical memory effect has been observed in Sm-doped ZnS nanocrystals and also in polystyrene powder doped with a fluorescent fulgide derivative. In this effect, not only the wavelength but also the angle of the incident laser light is memorized in the medium with high resolution even at room temperature. The reading is made in the form of a hole burnt in the fluorescence excitation spectrum. The mechanism is ascribed to the recording of the interference pattern of the multiple-scattered light through photo-bleaching and the reading through the spatial overlap integral between the modulated absorbance and the interference pattern of the exciting light. Various characteristics of this effect and its possible application to the high-density optical data storage are discussed.

At FNAL beam dump experiment DONUT, tau neutrino interactions are confirmed by the use of a modern emulsion technique. This is first direct evidence for tau neutrino in the history. Within secondary tracks of neutrino CC interactions, tau lepton is confirmed by the event analysis having a short decay track. Four clear events and one candidate are found in 203 prompt neutrino interactions. For four events a total of 0.4 background events is estimated both from charged charm decay and secondary interactions. These events are the evidence of tau neutrino.

Electron transport of nanoscale silicon devices are presented. Nanocrystalline-silicon quantum dots have been prepared by a novel pulsed-plasma process. Average dot diameter of 8nm with a small dispersion of 1nm has been obtained. Single electron tunneling has been observed from a single nanocrystalline silicon dot embedded in both planar single electron transistors and vertical transistors with a wrap-around gate. Ballistic transport has been observed in vertical transistors having gate length 20nm. Single electron memory effects are observed in various device structures. Finally, we propose NeoSilicon, a novel quantum functional material in which both dot size and interdot distance are precisely controlled.

Raman Scattering has proved to be a very successful technique in the study of carbon nanotubes, especially since the discovery of diameter distributions in the case of single-walled ones (SWNT's). In the paper, we recall the main results obtained recently on single-walled as well as multi-walled carbon nanotubes by using this technique. Also, we emphasize those obtained in SERS conditions when rough metallic surfaces of Ag or Au are used. Solvent effects will be in particular described, in terms of disorder but also chemical reactions taking place with the metallic support. Finally, we will report on investigations carried out on polymer/carbon nanotubes composites, in the case of PMMA used as polymer, when the nanotube concentration is changed. The interactions between the two components are interpreted from the behavior of the low frequency radial breathing mode.

Surfaces of nanocrystalline Si with different morphologies were terminated with Si-H_X bonds by a chemical treatment in HF solution or using hydrogen atoms dissociated from hydrogen molecules by a Pd layer deposited. Micro-Raman and Micro-photoluminescence (PL) spectra measured at room temperature on the same spot of the samples under He-Ne or Ar laser irradiation (LI) have been studied. The different Si-H_X (x = 1,2,3) stretching and wagging vibrational Si-H modes were readily revealed. The hydrogen desorption from Si-H_x bonds caused by LI led to a decrease in the PL efficiency. In addition, the reactive H atoms can readily chemisorb on the Si dangling bonds of the nanocrystalline Si, which are created by the hydrogen desorption from the stretching Si-H_x bonds.

A model, combining the effect of the matrix element of the Fröhlich interaction with the effect of the density of states of phonons, is proposed to clarify the origin of the Raman scattering lineshape in GaAs/AlAs multiple quantum wells(MQW), which has recently been assigned to the dips due to anticrossing of interface modes with the odd-order confined modes, rather than the peaks associated with the even-order modes. The numerical results based on this model have well reproduced main features in the resonant Raman scattering spectra of MQW with identical well width but different barrier widths and indicate that, when there exists the interface imperfection, the first several peaks in Raman spectra still result from the even-order confined modes, instead of the dips.

The X-ray photoelectron spectroscopy(XPS) and non-contact mode atomic force microscopy(NC-AFM) studies on the oxidation reaction at the SiO₂/Si interface, oxidation-induced atomic-scale surface roughness, and the oxidation rates at the initial growth steps of ultrathin oxides formed on Si(111) are reviewed.

New types of the Kondo effect are examined theoretically which are observable in quantum dots fabricated on semiconductors. First we show an enhancement of the Kondo effect in quantum dots with an even number of electrons, due to the competition between spin-triplet and singlet states. Our results explain recent experimental findings in “vertical” quantum dots. Second we investigate the Kondo resonant state in coupled quantum dots, which is characterized by a ratio of the dot-dot tunnel coupling to the dot-lead coupling.

There has been increasing interest and activity in the preparation and device application of ultrathin Iron (Fe) films grown on compound semiconductor substrates such as gallium arsenide (GaAs) and zinc selenide (ZnSe). In this paper a brief review on the preparation and characterization of such Fe-GaAs layer structures using the MBE technique, and realization of wideband microwave band-stop filters is presented. The Fe film-based devices possess an important advantage over their yttrium iron garnet (YIG) film-based counterparts in that for a given operating carrier frequency the former requires a much lower bias magnetic field. This is so because the saturation magnetization of the Fe films is more than one order of magnitude larger than that of YIG films. Accordingly, a much higher device operating carrier frequency with large electronic tunability may be achieved more readily in practice using the Fe-GaAs layer structures. An integrated-type microwave band-stop filter was fabricated in such layer structure through a sequence of chemical etching processes to form a microstrip transmission line. A frequency tuning range as large as 10.0 to 33.0 GHz has been accomplished. The experimental results are shown to be in excellent agreement with the theoretical prediction.

The formation of amorphous interlayer (a-interlayer) by solid state diffusion in diffusion couples has been one of the most challenging problems in condensed matter physics in recent years. The a-interlayer has been found to occur in all refractory metal/Si and a number of rare earth (RE) metal and platinum group metal and crystalline silicon systems. In this article, we highlight the progresses made in the past few years in the study of amorphous interlayers.

Charge transport properties such as temperature dependent dc conductivity [σ_dc(T)] and thermoelectric power [S(T)], electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS) for various Li salt (LiPF_6, LiBF_4, LiAsF_6, and LiClO₄) doped polyaniline (PAN) samples are compared to those of protonic acid (HCl) doped PAN (PAN-ES) samples. The room temperature σ_dc of Li salt doped PANs varies from 1 to 10⁻⁷ S/cm depending on dopants used. The σ_dc(T) of the systems follows a quasi one-dimensional variable range hopping model, which is similar to PAN-ES. The S(T) of PAN-LiPF₆ shows the metallic behavior. With increasing doping level, the insulator-conductor transition is observed in the results of σ_dc and the density of states obtained from EPR. From XPS experimetns, the doping level of the systems is estimated. The insulator-conductor transition of Li salt doped PANs is compared to that of PAN-ES samples and the charge transport properties of NaPF₆ doped PANs are presented.

We present our first-principles total-energy calculations which provide a detailed picture of adsorption and diffusion of a Si adatom on the plane and stepped H/Si(100) surfaces. The diffusion mechanism is very complex unlike that on the clean Si(100) surface and the activation energy of adatom diffusion is sensitive to the hydrogen coverage on Si surfaces. Reaction of the adatom with the step edges shows remarkable variances according to the step types. Calculated results agree well with the observed morphology change and epitaxial growth on H/Si(100).

Photoluminescence (PL) properties of Si-doped thin (5-13 nm) GaN layers grown on (0001) sapphire substrates at 760 °C by electron cyclotron resonance molecular beam epitaxy are studied. 12K PL spectrum for the undoped GaN layer shows a broad deep-level emission peak. For the Si-doped layers, the PL intensities for the band-edge peak and the Si donor-related peak are increased with increasing Si concentration, and the deep-level peak disappears for the sample with a Si concentration of about 1 × 10²⁰ cm⁻³. The activation energy for the nonradiative recombination is observed to increase with Si concentration, and it is estimated to be 17.7 meV for 4.5 × 10²⁰ cm⁻³ Si concentration. Atomic force microscopy measurement also shows the improvement of the surface morphology of grown layers with the increase of Si concentration. The results shows that the Si doping improve the crystal quality of GaN due to the decrease of defects.

The lateral diffusion behavior of 2D carrier gas in InGaN/GaN multiple-quantum-wells was studied using transient transmission measurements. Due to the large built-in piezoelectric field, well-width dependent diffusion behaviors were observed. For samples with well-width on the order of or smaller than the exciton Bohr radius, carrier diffusion was dominated by ambipolar-like diffusion due to the strong correlation between electron and hole wavefunctions. For samples with a well-width larger than the exciton Bohr radius, due to the separation of electron and hole wavefunctions, electron gas dominated diffusion behavior was found.

A systematic study on atomic layer epitaxy (ALE) of GaAs and AlAs thin films has been carried out by using trimethyl gallium and ethyldimethylamine alane as Ga and Al sources, respectively. For GaAs, the self-limiting growth of ALE occurs at just one monolayer (ML) per cycle. The mechanism of the growth is explained in terms of either adsorbate inhibition model or selective adsorption model. On the other hand, as to ALE-AlAs, self-limiting growth modes accompanied by one-, two- and three-monolayers per ALE cycle have been clearly presented. Each growth mode shows unique dependence of growth temperature on carbon contents. It can be concluded that one monolayer self-limiting growth proceeds with the conventional adsorbate inhibition model, whereas the self-limiting growth with two- and three-monolayers can only be explained by the formation of metallic Al layers. We also point out that atomic configuration of the layer may depend on the substrate temperature.

Current - voltage (I-V) characteristics were measured for Au/n-Si Schottky diode at room temperature in air and in NO_x. The derived Schottky barrier height, the ideality factor and the reverse current were significantly changed with the incorporation of NO_X.

New experimental evidence for the aggregation of the near-IR bands in BaFBr:Eu²⁺ single crystals has been demonstrated through a series of measurements on the nonrecombination process in additively colored crystals, the time-resolved absorption spectra, the IR emission spectra, and their temperature dependence. It was found that the origin of the bands is attributed to a cluster of F(Br⁻) centers.

The capacitively loaded slow-wave resonators exhibiting a large resonant length have been well known as circuits for effectively miniaturizing microwave devices. However, their conductor loss caused by the capacitive loadings affects their performance and thus limits their applications in miniaturization. This problem can be overcome by using low loss superconductors, which are possessing ten- to thousand-time lower surface resistance than that in normal conductors at microwave frequencies. A Butterworth bandpass filter that has been designed by combining capacitively loaded slow-wave resonators and the low-loss HTS for material is presented in this study. With very small circuit sizes and the excellent frequency responses, the filter demonstrates the great capability of improving the circuit performance by low-loss superconductors when miniaturized.

The complementary wavelike and particlelike natures of photons allow one to ascertain the presence or absence of an object without any photons being absorbed. This counterintuitive measurement is called an “interaction-free measurement”. To investigate the potential of the measurement in imaging applications, we have made “classical” interaction-free measurements of a photographic film using a high-finesse Fabry-Perot resonator. We have demonstrated that a photographic film's shape is imaged on an identical piece of film without exposing the first film. Moreover, we have demonstrated that a positive and a negative images of a photographic film's shape are simultaneously obtained without exposing it.

The magnetosphere around a rotating black hole plays an essential role in extracting energy from the hole. We consider the structure of stationary axisymmetric force-free magnetosphere of a black hole using the “3 + 1” formalism. Given the electromagnetic field configuration in the magnetosphere, one can calculate the electric charge induced on the stretched horizon of a rotating black hole. For a stellar black hole with magnetic field of 10¹⁵G at the horizon, it is found that the amount of the induced charge is much smaller than the extremal charge of the black hole and is comparable to the Goldreich-Julian charge on a magnetar.

Several cosmologically distant astrophysical sources may produce ultra-high energy cosmic neutrinos (E_ν ≥ 10⁶ GeV) of all flavors above the atmospheric neutrino background. I study the effects of vacuum neutrino flavor mixing on this cosmic neutrino flux. Prospects for observations of these ultra-high energy cosmic neutrinos in large underwater/ice neutrino telescopes are also briefly discussed.

The Alpha Magnetic Spectrometer detects a large amount of particles below rigidity cutoff. Those high energy particles create questions related to radiation belts and atmospheric neutrinos. To understand the origin of these particles, we use a trajectory tracing program to simulate particle trajectories in realistic geomagnetic field. The complex behaviors and large e⁺/e⁻ are explained here.

Hydrogen deficient carbon clusters HC_n and H₂C_n are thought to resemble the crucial link between naked carbon clusters such as C₂/C₃, polycyclic aromatic hydrocarbons, and carbon rich interstellar/circumstellar grains. To fully understand the astrophysical significance of these grain nuclei condensation processes, it is of paramount significance to elucidate first detailed mechanism how these simple precursors are formed in outflow of carbon rich stars. Due to this importance, we initiated in our laboratory a systematic research program to investigate reactions of C₂ and C₃ clusters in their singlet X¹Σ_g⁺ ground state with unsaturated hydrocarbons C₂H₂ and C₂H₄ employing the crossed molecular beam technique. These experiments yield the first doubly differential reactive cross section on the cluster versus H/H₂ exchange and supply valuable information on the stepwise growth of carbon rich structures in extraterrestrial environments. Preliminary data analyses identify the CCCCH, CCCCH, and CCCCH₂ isomers which were identified in the circumstellar shell of IRC+10216 together with hitherto unobserved interstellar n-C₄H₃, n-C₅H₃, and CCCCCH₂ radicals.

Crystal scintillators offer potential advantages for the pursuit of low-energy (< 1 MeV) low-background neutrino and astro-particle physics experiments. An experiment towards a ∼ 500-kg CsI(Tl) as both target and detector is now being intensely pursued by a Collaboration comprising more than 40 scientists from Taiwan, Mainland China and the United States. The experiment will be performed at the Nuclear Power Plant II in Taiwan, using reactor neutrinos as a probe. The goal of the first phase will be the studies of low energy neutrino interactions. The merits of the crystal scintillator approach, the prototype performance and status of the pilot experiment will be reported. Future prospects will be discussed, which include the possibilities in dark matter WIMP searches and low energy solar neutrino studies.

In order to understand, and ultimately optimize plasmas for various purposes, we have to know spatio-temporal distributions of (1) electric fields, (2) electron density and temperature (or EEDF itself if it is away from Maxwellian), and (3) reaction products. The authors have extensively explored potentials of laser-aided plasma diagnostics (LAPD) for this purpose and applied it to various discharges. These are developments and applications of laser optogalvanic spectroscopy (LOG) and laser-induced fluorescence (LIF) to detect Stark effect for (1), Thomson scattering to measure electron density and temperature/EEDF for (2), and LIF, Raman scattering, Rayleigh scattering, and ultra-violet absorption to measure density and temperature of atoms and molecules for (3). Some examples of these are described, and implications of these measurements to actual processes are discussed.

We introduce the 3-kn symbol and the S symbol as novel vector-coupling coefficients. They exhibit the Regge symmetries more elegantly than the Wigner 3-j symbol, and the non-negative integer arguments of these new coefficients lead to concise algebraic expressions with simple phase factors.

We summarize experimental results to date which support the microscopic theory of turbulence. The theoretical basis of the predictions for the onset of turbulence is reviewed. From this fundamental basis, other predictions are made. Finally, the meaning of these predictions and confirmations are discussed, resulting on new fundamental theoretical questions, and possibly a new field of experimental work.

The behavior of photon-limited light is discussed in reference to its use in confocal microscopy. A ray-tracing based simulation of photons passing through a confocal optical imaging system is performed with the photon propagation determined by the photon distribution function at the photodetector. The formation of the image of a point source is considered with regard to how well the approximate distribution of photodetector events approaches the classical three-dimensional point spread function (PSF) as the number of detected photons increase. We find that the normalized mean-square error between the detected photon distribution function and the classical PSF (very high SNR) has a power-law behavior varying as N-1.001, where N is the number of detected photons.

Periodic structures of a transparent dielectric medium varying in a scale of optical wavelength are called photonic crystals. In the 2D array of dielectric microspheres, there appears dissipative 2D photonic band, the peculiarity of which predominates its electromagnetic near-field structure on the array. We report the experimental evidence of photonic band effects on self-assembled ordered monolayers of polystyrene microspheres. The photonic band structures are obtained from the far-field optical transmission spectra. The influence on the photonic bands is investigated by varying the ratio of the particle diameter to the inter-particle distance. Different eigenmodes of the photonic bands are excited by the near-field light emitted from the microprobe of a scanning near-field optical microscope (SNOM), leading to the resonant change in the contrast patterns of SNOM images. The light propagation along the layer is observed in fluorescence excitation SNOM images that manifest the dissipative photonic band.

An electronically addressed spatial light modulator (SLM) is designed for optical information processing and display. One of the candidates for SLM material is a nonlinear organic polymer of PMMA doped with Disperse Red 1. The measured electrooptic coefficient r₃₃ was 2.9pm/V at the wavelength of 632.8nm in the case of 75MV/m of poling voltage. To increase modulation efficiency, a resonator structure of a material is considered, and the use of complex refractive index modulation is also discussed.

By using newly-developed apparatus, we have observed the energy spectra of the field electron emission from a niobium superconducting emitter and detected a sharp peak at the Fermi level in the spectra with an energy width of ~ 20 meV at 10nA. The extra peak decreases with increasing accelerated voltage, keeping the peak shape. In addition, we have found the drastic change in total emission current around Tc (= 9.2K).

We define the multimode sum- and difference-squeezing appearing in multiwave mixing processes. We show that these kinds of multimode higher-order squeezing are converted to normal squeezing of the output sum- and difference-frequency mode. The conditions for the modes to be sum- and difference-squeezed are established which would provide a good guide for preparing the input modes to produce the squeezed output mode through a nonlinear medium. We also prove that the operators characterizing the general multimode sum-squeezing form a SU(1,1) Lie group for an arbitrary mode number whereas those characterizing the general multimode difference-squeezing are connected to a SU(2) Lie group only for N=2.

Wear is a progressive removal of surface portion of solids caused by frictional action. The phenomenon is familiar, but the origin or fundamental mechanism of wear of materials is not yet clarified hitherto. To determine what mechanism governs the wear of solids, the author carries out an experimental study on virgin/virgin rubbing. If the mechanism of wear is one of cutting, surface damages are observed and wear particles are produced even in the virgin/virgin rubbing. If wear is governed by mutual adhesion of sliding materials, no wear particles would be generated but only mutual material transfer is observed. If wear mechanism is governed by fatigue fracture of the surface portion, neither surface damage nor wear particle formation would occur. Experimental results show that the origin and fundamental mechanism of wear is adhesion of mating materials.

Multi-wave x-ray interaction takes place when several sets of atomic planes of a 2-d or 3-d crystal are brought into position to diffract an incident x-ray wave. With synchrotron radiation, it is possible to realize three-wave interaction for crystal surfaces and thin films by tuning the incident photon energy. For a crystal bulk, rotation of the crystal is necessary for multi-wave diffraction to occur. In this paper, we report recent synchrotron experiments of multi-wave diffraction for 2-d surface in-plane lattices and 3-d crystals of macromolecules. The intensity variation of diffracted waves due to multi-wave interaction is observed and the associated phases of reflection are also determined. The mechanism of the interaction will be discussed.

In order to analyze the spatial distribution of a magnetic neutral loop discharge (NLD) plasma, the electron density (ne), electron temperature (Te) and ion flux were studied experimentally and numerically. The experimental results showed that the Te and ion flux have a peak on the neutral loop (NL) and migrated along magnetic field lines. In contrast, the electron density had a peak at a position inward from the NL along its radius. Analyses of the electron behavior using a 3-dimensional model showed that there exists an electron -trapping region at a position radially inward from the NL due to magnetic mirror effect.

The gyrotrons developed at Fukui University (“Gyrotron FU series”) are high frequency, medium power devices, covering a broad frequency band in the millimeter and submillimeter wavelength region. Currently the “Gyrotron FU series” consists of eight gyrotrons. Some distinguishing features of these devices such as frequency tunability from 38 GHz to 889 GHz as well as frequency and amplitude modulation of generated radiation are described in this paper.

Effects of cathode in Plasma focus were investigated using two types of cathode electrode (I) sixteen copper-bars arranged along the envelope of cylinder and a (II) conventional cylindrical tube. The inductance is smaller in the latter than in the former. As a result, the period is shorter, and the peak current is higher in the latter. In spite of that, the neutron yield at the optimum pressure was higher in the former cathode than in the latter. The influence of plasma escaping through between bars was checked by using glass cover enclosing just outside of the bar cathode.

We initiated strong coherent acoustic phonon oscillations in InGaN/GaN multiple-quantum-wells using a femtosecond ultraviolet excitation pulse, taking advantage of the large piezoelectric field in the InGaN wells. The coherent control of the initiated acoustic phonon oscillation was achieved using a second femtosecond ultraviolet control pulse. The phase and oscillation magnitude control was successfully demonstrated

The production of the O(¹D) was employed to investigate the Rydberg states of O₂ in the wavelength region 105-130 nm. Excited states of E and E'³Σ_u⁻ and F and F' ³Π_u were identified. Several bands of overlapping E and F states were also found. Excited states of O₂ are strongly perturbed, as evident by their irregular vibrational spacing.

Motivated by the developments in the theory of fluid turbulence we derive a single pipe flow equation using a projection and perturbation formalism that enables us to obtain velocity profiles in the laminar and tubulent regimes. We display the non-stationary velocity profiles and show that the model is consistent with a theory where structure of the molecule plays a role in explaining turbulence.

The characteristic vibrations of tetravalent metallo -Pc (TiOPc, VOPc) have been studied by Raman and resonance Raman spectroscopy. From the relationships between the Raman frequencies of the ring and the metal-ligand distance d (Me- N) established for a large number of the metallo- Pc, the geometry parameter of these molecules is evaluated.

The quality of the controllable optical index films based on silica photonic materials for integrated optics depends mainly on the thermal treatment. The microstructural properties of TiO₂ in (1−X) SiO₂ XTiO₂ system during the curing process were elucidated by using of the thermo-, X-ray analysis, and MicroRaman. In regard to active materials, the fluorescence spectra and it's lifetime of Eu ³⁺ doped SiO₂ /TiO₂ films were measured to investigate the influence of treatment temperature, activators concentration and fabrication conditions of the doped film systems.

An unexpected profile has been found in the coherent two-field excitation spectrum of a two-level system. This profile is dispersive and its width can be as small as 0.02Γ, where Γ is the natural linewidth of the excited state. Our study shows that the profile is due to the ultranarrow resonance in the spontaneously transferred population convoluting the Mollow dispersion.

In this paper we present a novel design of a quasi-optical system for conversion of gyrotron outputs into Gaussian beams. It consists of a quasi-optical antenna, focusing mirrors and a filter which removes the side lobes of the beam. The system is capable to convert three TE_0n mode outputs into Gaussian beams.

An electron beam ion trap (EBIT) is the device which can produce and trap very highly charged ions (HCIs). We have been using the Tokyo EBIT to study atomic physics of HCIs. The present experimental subjects are spectroscopic studies in the X-ray and the visible range, studies of collision processes with matter (electrons and surfaces), and so on. Recent results of them and future plans are presented.

The extensive design effort was focused on two major aspects of the KSTAR project mission, steady-state operation capability and “advanced tokamak” physics. The steady-state aspect of mission is reflected in the choice of superconducting magnets, provision of actively cooled in-vessel components, and long-pulse current-drive and heating systems. The “advanced tokamak” aspect of the mission is reflected in the design features associated with flexible plasma shaping, double-null divertor and passive stabilizers, and internal control coils. Substantial progress of engineering effort has been made on superconducting magnets, vacuum vessel, plasma facing components, and power supplies. The new KSTAR experimental facility with cryogenic system and de-ionized water-cooling and main power systems has been designed, and the construction work has been on going for completion in year 2004.

Recent development of the nonequilibrium relaxation method, which is an analyzing method of the equilibrium state and the phase transition through the relaxation functions from a nonequilibrium state to the equilibrium state, is reveiwed.

Local properties of an alternative multifractional Brownian motion based on the generalization of fractional Brownian motion of Riemann-Liouville type are studied.

The interfacial properties of a homopolymer [polybutadiene, (PB)], a terpolymer [brominated poly (isobutylene-co-p-methylstyrene), (BIMS)], and a random copolymer [poly (styrene-co-butadiene), (SBR)], are reported. Neutron reflectivity (NR) was used to study the interfacial structure and dynamics at a nanometer scale. The results were complemented by small angle neutron scattering (SANS), which was used to probe the interfaces of bulk samples. Both NR and SANS data of PB/BIMS blends suggested that they are immiscible at room temperature, and thermal treatment moderately improve their miscibility.

The probability distributions of clusters within wide range of cluster-size on square lattices are obtained by Monte Carlo (MC) simulations for variations of density. We show that each distribution in experiments obeys the statistics led by optimization of Tsallis entropy with constraints, and also such a new approach gives a possible explanation for a root of the power law in percolation phenomena.

By spectroscopic analysis of visible light that is emitted from the tip-sample gap of the scanning tunneling microscope (STM), one can obtain information on the electronic transitions in individual and specific surface nanostructures with atomic spatial resolution. We have used this technique to investigate the electronic transitions in individual quantum wells of Al_xGa_1−xAs/GaAs structures and at different locations within a single well. Also an atomically localized electronic transition on the reconstructed Au(110)-(2×1) surface was found by this method.

The structure of clean and oxygen-covered Cu(210) is studied by quantitative low energy electron diffraction (LEED) and scanning tunneling microscopy (STM). Quantitative IV-LEED of clean Cu(210) shows contractions in the first two interlayers and expansion in the third interlayer, consistent with theoretical studies using semi-empirical models. STM and IV-LEED data show the formation of a stable Cu(210)-(2×1)O reconstruction as well as other (n×1) reconstructions after oxygen adsorption at various substrate temperatures. Quantitative IV-LEED analysis of the (2×1) structure confirms an added row model with oxygen at the bridge sites along the [001] direction.

Structural, transport and magnetic data were reported for the Pr_1+xBa_2−xCu₃O_7−y or 1212-type Cu(Ba_2−xPr_x)PrCu₂O_7+y system (−0.2 ≤ x ≤ 1, −0.4 ≤ y ≤ 1). The phase diagram shows two structural symmetry transitions, from orthorhombic 1212C (C for CuO chain) O(I)-phase (space group Pmmm) to tetragonal 1212 T-phase (P4/mmm), and then to a new type of orthorhombic 1212 O(II)-phase (Cmmm). Electrical resistivity data (represented by room temperature resistivity ρ(300 K)) indicate that this system is not favorable for metallic state and no superconductivity can be detected for these Mott-insulating cuprates. Magnetic susceptibility data show that, regardless of the structural transitions, antiferromagnetic Pr ordering with anomalous high Néel temperature T_N(Pr) decreases monotonically and smoothly with increasing x and/or y parameter except in the O(II) phase region.

Cu-1234 (CuBa₂Ca₃Cu₄O_12−y) has a high T_c >117 K (= one and a half time of 77 K) even in over-doping region, a low superconducting anisotropy (γ =1.6), a long coherence length along c-axis (ξ_c = 1 nm) and a small penetration depth (λ_c = 220 nm). Therefore, it is capable of becoming the best performance superconductor with a high J_c {>20 M A/cm² (77 K, 0 T), 0.5 M A/cm² (77 K, 10 T)}, a high H_irr {30T(77 K)} and a low surface resistance {30 μ Ω (77 K, 10 GHz) }. These superconducting properties can be derived from its unique composition, lattice structure and electronic structure on the basis of microscopic data of coherence length, penetration depth, hole concentration, NMR measurements and band calculation. Sustainable high T_c in over doping Cu-1234 were achieved by the selective over-doping effect, and moreover high T_c‵s of 132 K in Cu_1−xTl_x− 1223 and 126 K in Cu_1−xTl_x−1234 were attained by homogeneous optimum-doping effect.

The thin film preparation processes of Cu-1234 system have been developed by applying new techniques such as APE(amorphous phase epitaxy) and SAE(self assembling epitaxy) methods for Cu_1−xTl_x−1234 and −1223 system. The thin films of Cu_1−xTl_x− 1223 have given a high J_c =20 M A/cm² (77 K, 0 T) and =0.4 M A/cm² (77 K, 10 T) and its data extrapolate a high H_irr ∼ 30 T at 77 K.

Recently, a melting of the charge ordered state on decreasing the temperature, i.e. reentrant behavior, has been found in Pr_0.65(Ca_0.7Sr_0.3)_0.35MnO₃ and in LaSr₂Mn₂O₇. The following theoretical models of reentrant charge ordering in the above manganites are considered: i) the square lattice extended Hubbard model with both on-site and nearest neighbor Coulomb repulsion, ii) the extended double exchange model, where the reentrant charge ordering appears due to the dependence of the hopping on the temperature resulting from double exchange.

Magnetic domain images of nanometer size magnetic features are obtained using MFM with low magnetic stray field and high-coercivity MFM tips. The high-resolution MFM images show details in the domain structure of thin film permalloy elements. The “ripple” structures are observed in the elliptical and round samples connecting the vertex and the edge. This effect is due to the edge roughness and obtained by micromagnetic simulations as well. The domain structure in rectangular and elliptical thin-film elements is observed by MFM method and their variation can be attributed to the different aspect ratio of the elements and different initial conditions. Micromagnetic simulations reproduced many features observed experimentally.

Spin-dependent tunnel magnetoresistance of Co/Al₂O₃/Co_X/NiFe was studied as a function of the thickness of Co_X. The thickness (X) of the doped Co was varied between 0.8nm and 2.0nm. An increase in tunneling magnetoresistance ratio from 3.5 % to 9 % was found for the spin-dependent tunnel junctions with 0.8 nm to 2.0 nm of doped Co_X. The enhanced tunneling magnetoresistance may be attributed to the increasing in the effective polarization of the tunnel electron due to the spin-filtering effect from the doped material.

The Gd₅(Si_0.5Ge_0.5)₄ compound is now considered to be a promising material for magnetic refrigeration applications at near room temperatures. In this paper we focus on the role of the substitution of different rare earths for Gd in the Gd₅(Si_0.5Ge_0.5)₄ compound. It has been shown that isostructural intermetallic R₅(Si_0.5Ge_0.5)₄ compounds with R = Nd, Pr, Tb, Dy, Ho and Er were formed. Magnetization measurements, however, suggest that these compounds show a great variety of the magnetic structures. Magnetocaloric effects have been determined for the compounds with Nd, Gd and Tb. It has been found that apart from the Gd compound, giant magnetocaloric effect has also been observed in the Tb₅Si_0.5Ge_0.5)₄ compound.

By means of an AFM we observed a Si(111) surface with nanoparticles in ambient and manipulations of nanoparticles in the tapping mode. A surface damage as a scratched trough simultaneously occurs at the Si(111) surface during manipulating a nanoparticle, but it disappears in the next scan. This implies that the scratched trough is a artifact due to the nanoparticle manipulation. This paper presents AFM images of the nanoparticle manipulation and virtual scratched trough, and gives a possible explanation to understand the presence and absence of the virtual scratched trough.

With a variable-temperature scanning tunneling microscope (STM), a new type of Si magic clusters on Si(111) surfaces has been discovered and investigated. Using Arrhenius analysis, the activation energies and pre-exponential factors for the jumping rates along different pathways are derived. Moreover, the individual events of electromigration have been identified to be Si magic clusters. The directed motion along the electric field of the heating current and thermal migration are determined separately and quantitatively. The anisotropic decay of non-equilibrium structures associated with an electric field is also discussed.

We investigate the electron correlation effects on light emission from dimers on Si(001) induced by scanning tunneling microscope (STM), with the aid of the Hubbard model. In the model, electron transfer between the STM tip and a dimer in the vicinity of the tip accounts for light emission. We demonstrate by the Green function method that the light emission intensity reflects the electronic density of states. As a result, it is suggested that the fundamental parameters related to the electron system, i.e. the electron hopping integral between dimers and Coulomb interactions between electrons in a dimer with opposite spins, can be estimated from the light intensity.

Lead (Pb) is known to grow on Si(111) with the Stranski-Krastanov mode at room temperature. That is to grow in 3D islands following the completion of the wetting layers. With the variable temperature scanning tunneling microscopy, we study the low temperature growth of Pb films on the Si(111)-7×7 surface at T∼ 200 K. Flat top crystalline Pb islands are formed at this temperature and notably, they acquire some critical and magic thicknesses. Among them, those island's height equivalent to seven atomic layers are especially dominant. These islands thus grown display peculiar properties that cannot be categorized into any of the conventional growth modes. A plausible explanation is based on the quantum size effect, which could play an important role in the low temperature growth of epitaxial thin films.

The YBa₂Cu₃O_7−δ(Y123) and Bi₂Sr₂CaCu₂O_8−δ(Bi-2212) superconducting thick films were prepared by a partial melt method. The Al₂O₃ polycrystal has been used as a substrate for processing the films. The films are pure of the superconducting phase with a T_conset of about 92K and 85K for Y123 and Bi-2212, respectively. The melt temperature T_m considerably affects on critical current density of the films. The best J_c value of about 6×10²A/cm² is obtained at 30K and zero field for the Bi-2212 film prepared with T_m=885°C. The Y123 thick films have lower Jc value. It is supposed to be related with the film microstructure, intergrain phases due to the diffusion of Al ions from Al₂O₃ substrate.

Bi₂(Zn_1/3Nb_2/3)₂O₇, BiZN, thin films have been succesfully developed using pulsed laser deposition (PLD) method. The crystalline phase can be obtained when the films were deposited at the substrate temperatures 450– 600° C. The refractive index (n) and absorption coefficient (κ) of BiZN thin films were investigated by optical transmission spectroscopy. The optical constants n and κ are insensitive to the PLD parameters.

Based on a theoretical model proposed for interchain coupled quasi-one-dimensional organic ferromagnets, the distribution of the charge density and spin density are studied. The next-nearest neighboring hopping interaction, the strong electron-phonon coupling and electron-electron interaction are taken into account. It is found that the SDW is modulated by the CDW. The interchain coupling causes the transfers of charge density and spin density between the main chain and side radicals, and reduces the critical next-nearest neighboring hopping at which the second CDW appears. It is also found that the interchain coupling and the next-nearest-neighbor hopping integral destabilizes the ferromagnetic ground states.

With the t-J based spin polaron Hamiltonian as the interaction term in the S-matrix, the finite temperature Green's functions for the holon and spin wave are discussed in the strong and weak coupling limits. The expressions for the entropy and specific heat are subsequently obtained from the thermodynamic potential by the linked-cluster expansion method. The generalization of the Wiedemann-Franz law is then treated in this theoretical framework. The moments of spectral functions for the holon and spin wave are then discussed along with the magnetic spin susceptibility and Kubo electrical conductivity in the concluding section.

In this paper we derive the mass of the vortex from the effective Lagrangian proposed by Ao and Thouless[1] which contain the magnus force and dissipation terms. By using the Feynman-Jensen variational principle we obtain the dynamic and cyclotron mass of the vortex. We also discussed the finiteness of the dynamic mass.

The scattering and guiding of waves by photonic bandgap structures is formulated using rigorous modal fields. Such a modal solution can be represented and interpreted in terms of electrical transmission-line networks by suitably generalizing ideas and concepts used in conventional circuits. Such an approach not only greatly facilitates finding the solution in a multilayer structure consisting of photonic bandgap materials, but provides physical insights into the problem. To illustrate the usage of the present approach, we present results for guided waves in a photonic bandgap structure.

Investigations of crystal structure and dielectric measurements in Pb_1−x(Li_1/2La_1/2)_xZr_1−yTi_yO₃ solid solutions at the phase transition from paraelectric state into ordered states near the triple Ferroelectric – Antiferroelectric – Paraelectric point of the “Ti-content-Temperature” phase diagram are carried out. Analysis of shape of characteristic X-ray lines is indicative of the presence of the two-phase nuclei with ferroelectric and antiferroelectric types of dipole ordering in the crystal lattice of solid solutions above the point of paraelectric phase transition (the Curie temperature). The relation between the presence of the two-phase nuclei in paraelectric phase of the compound and the diffuseness of the ordering phase transition is discussed.

The exact as susceptibility of a superparamagnetic particle is calculated here directly from Brown's Fokker-Planck equation. Three response regimes are recognized: overbarrier, intrawell and rigid at low, medium and high frequencies respectively. The form of the perturbed probability distribution is discussed in detail.

Energy relaxation dynamics in a simple fully quantum model of electron-phonon system is numerically investigated.

The spin-dependent local field corrections G_{σ, σ′}/ (q, ω) of a spin-polarized electron gas(SPEG) are examined within a genralized RPA. Numerical results of G_{σ, σ}/ (q, 0) for both the majority and minority spin electrons of SPEG show a complicated but interesting behavior as one varies the spin polarization ζ of the SPEG. A pronounced maximum in G_{σ, σ}/ (q, 0) is observed and the location of the peaks are found to depend strongly on the values of ζ. We also show some numerical results of the mixed susceptibilities χ^em and χ^me, which are finite and not identical in SPEG.

To unravel the mystery of the recently observed giant magnetic moments in Fe and Co in Cs films, orbital-polarization corrected relativistic spin density functional calculations have been performed. Unlike other transition metal systems where the orbital magnetic moments are quenched, Fe and Co in Cs are found to possess a giant orbital moment of 2∼3 μ_B along with a large spin moment. Also, these free atom-like spin and orbital magnetic moments would not be squashed under large lattice contractions up to 23 % around the impurity atoms. The induced moments on the host atoms are small. The results offer an explanation of the origin of the giant moments in Fe and Co in Cs films.

Form factors of πNN, πNΔ, KNΛ and KNΣ have been calculated in the Chiral Bag Model. Coupling constants were also estimated in the limit of vanishing momentum.

Lifetimes and energy spectra of protons emitted in the nonmesonic weak decay of , and _ΛFe hypernuclei have been measured by the (π⁺, K⁺) reactionusing the large acceptance kaon spectrometer(SKS) at KEK 12 GeV PS. The lifetimes over the measured mass region were found almost constant within the statistical uncertainties at about 80 % of that of a free Λ. The proton energy spectra demonstrated suppression of the proton yields in the energy region above 40 MeV compared with any available models. It suggests large Γ_n/Γ_p ratios for the three hypernuclei and the “Γ_n/Γ_p puzzle” remains.

The total cross section for the kaon photoproduction on the nucleon has been calcualted in the framework of the Chiral Bag Model(CBM). The KNΛ and KNΣ coupling constants are extracted from the γ + p → K⁺ + Λ(Σ) process near the K⁺– threshold in CBM.

The critical density of neutral pion condensation is investigated by using a new set of Landau-Migdal parameters, which are derived from a recent experimental data on the quenching factor of Gamow-Teller giant resonance. The particle-hole and delta-hole polarizations of the pion selfenergy are calculated based on the relativistic framework and compared with several nonrelativistic formulae.

It is shown that the relativistic calculation gives higher critical densities than those of the nonrelativistic calculations. It is confirmed in the relativistic calculation that “universality assumption” leads to so-called “wall” in the critical density and the wall disappears in the present calculation based on the findings of the experiment of Wakasa et al. on the quenching of the Gamow Teller strength.

The atomic Schwinger-Dyson(ASD) formalism is presented for an application to atomic structure. The ASD formalism consists of coupled Dyson equations of photons and electrons. Because it includes electron self-energies in nonperturbative way, higher-order correlations beyond the Hartree-Fock approximation are takes into account. The coupled Dyson equations of electron, nucleon and photons are derived based on a functional method. It is shown that this treating of the condensed fields naturally leads to tadpole energy, which cancels a half of Hartree energy. A general representation of photons is derived by using projection operators and by solving an inverse matrix problem. Thus, similarities and differences between ASD and traditional methods such as mean-field theory or Hartree-Fock are discussed.

A solution to the generation puzzle based on a nonabelian generalization of electric-magnetic duality is briefly reviewed. It predicts 3 and only 3 generations of fermions and explains the hierarchical mass spectrum as well as the main features in both the quark and lepton mixing matrices. A calculation to leading perturbative order already gives reasonable values to about half of the Standard Model parameters.

The process is investigated within the framework of the Standard Model with three families of quarks. This process receives contributions from both the electroweak penguins and the box diagram. The calculation is performed at C.M. energy E_tot above 2M_W, in order to investigate the effects of new threshold associated with the internal two W-boson states. It is observed that the form factors, for the electroweak penguins and the box diagram, exhibit an approximate degeneracy. This in turn leads to the separation of the dynamic factor from the K-M matrix factor in the expressions for both the scattering cross section and the scattering rate asymmetry parameter. The cross section is found to have a rapid drop below E_tot = 2M_W, before rising rapidly at 2M_W, and then tapering off gradually after that. The asymmetry varies rapidly below 2M_W because of this rapid drop in cross section, but becomes rather flat above 2M_W. Two final states are considered, namely and . In both cases, σ ≅ 10⁻⁵ pb and a ≅ 0.2×10⁻⁵ at E_tot = 180 GeV.

We describe how one can get the exact one point funtion, vacuum expectation value of vertex operator of affine Toda field theory using the property of the perturbed conformal field theory.

We find the most general low energy dynamics of 1/2 BPS monopoles in the N = 4 supersymmetric Yang-Mills (SYM) theories when all six adjoint Higgs expectation values are turned on.

Preliminary result of the proton-antiproton pair production from two-photon collisions at LEP II energies is presented. Analysis method based on antiproton annihilates in EM calorimeter separates antiproton from other negative hadrons and electrons. The proton-antiproton pair production rate is also benefit from high luminosity function due to the highest energy available from LEP II energies. Backgrounds due to mis-identification, feed down, e.g., Σ⁺ → pπ⁰ (and its charge conjugate) or from extra π°^'s are examined.

A new category of phenomena is predicted in which fermions of different flavours can transmute into one another, for example e → μ or e → τ, as a consequence of the ‘rotating’ mass matrix due to renormalization. As examples, calculations will be presented for various such processes. Some of these could be accessible to experiments in the near future.

Perturbative unitarity can be implemented and exact unitarity can be restored in perturbation theory by suitable parametrizations. The basic ideas for such parametrizations are discussed, and simple examples to illustrate the formalism are given.

We report the preliminary R values for all the 85 energy points scanned in the energy region of 2-5 GeV with the upgraded Beijing Spectrometer (BESII) at Beijing Electron Positron Collider (BEPC). Preliminary results from the J/φ data collected with both BESI and BESII are presented. Measurements of the branching fraction of the φ(2S) decays and the φ(2S) resonance parameters are reported. The future plans, i.e. significantly upgrade the machine and detector are also discussed.

A personal perspective is given on physics of charmless rare B decays: 1997 – 2003.

The K2K experiment is the first long baseline neutrino oscillation experiment. At this moment, 2.29 × 10¹⁹ protons on target were accumulated, which was about 20 % of the goal of the experiment. We observed 27 fully-contained events at Super-Kamiokande(in the 22.5 kton fiducial mass) and the expected number of events is in the case of no oscillation.

Results on atmospheric and solar neutrino analyses at Super-Kamiokande are presented. The whole data set of atmospheric neutrino is consistently explained with an assumption of pure ν_μ⁻ν_τ oscillations. The allowed range of parameters is 1.4 × 10⁻³ < Δm² < 5 × 10⁻³ eV² and sin² 2θ > 0.88 at 90% C.L. On the other hand, we found pure ν_μ⁻ν_sterile oscillations are disfavored with 99% C.L. From solar neutrino data, we obtained ⁸B neutrino flux ratio to the prediction of the standard solar model to be . The flux difference of daytime and nighttime is 1.3σ. The energy spectrum is consistent with expectations. By examining daytime and nighttime spectra, we found the small mixing angle solutions and vacuum oscillation solutions which satisfy the observed fluxes of solar neutrino experiments are disfavored with 95% C.L. for ν_e⁻ν_active oscillations. Similarly, ν_e⁻ν_sterile oscillations are also disfavored.

We highlight new physics at Fermi Lab. The discovery of the Top Quark and studies of its properties are reviewed. We summarize recent results on b physics, electro-weak physics, and searches for the Higgs particle and Supersymmetry. With the new Main Injector accelerator and major upgrades to the Tevatron, CDF, and DO almost complete, we present the prospects for new physics in the next few years. We also briefly describe the recent direct observation of the tau-neutrino, the new BTeV Experiment, the neutrino physics at the Main Injector, and other physics and plans at Fermi Lab.

Recent physics results from the experiments at the CERN e⁺e collider LEP2 are summarized. In particular W-boson physics, Higgs boson searches, searches for supersymmetric particles are discussed.

The basic aim of physics studies at the LHC is to unravel the mechanism responsible for the spontaneous symmetry breaking in the Standard Model (SM). In the currently accepted theoretical picture, this translates into finding ‘direct’ experimental evidence for the Higgs sector. TeV scale supersymmetry (SUSY) provides a very attractive solution to the ‘naturalness’ problem that theories with elementary scalar fields have. Hence in this talk I will summarise the physics potential of the LHC for searching for Higgs and Supersymmetry as well as for measurement of the parameters of the Higgs sector and the SUSY model. Theories with localised gravity (and large extra dimensions) give a credible option to have Standard Model without the attendant ‘naturalness’ problems. I will therefore also summarise the potential of LHC to probe these ‘large’ extra dimensions.

We review, in this article, physics opportunities of the linear collider and issues on the detector. We also discuss a role of the γγ, eγ and e⁻e⁻ options in addition to the e⁺e⁻ collisions.

No abstract received.

I summarise the activities of the different members of the SUSY working group. There have been two major areas of activity: 1) precision measurements of the SUSY particle masses/couplings and hence those of the SUSY model parameters, 2) investigations into SUSY searches at e⁺e⁻, γγ, γe and e⁻e⁻ colliders, in the non-standard scenarios such as explicit CP violation, R-parity violation and Anomaly Mediated Supersymmtery Breaking. In addition there have been studies which looked at the effect of ‘large’ extra dimensions at the various colliders mentioned above.

In order to discover and study higgs boson and to search for physics beyond the standard model, R&D's of linear colliders and thier detectors are going on. Design and performances of the JLC detectors are briefly described.

Progress is reported on research and development into the technologies and techniques for the construction of a beam profile monitor for a linear collider interaction region. Based upon measuring in detail the copious production of electron-positron pairs through beam-beam interactions, such a “pair monitor” has been proposed previously. This report details the results of performance and radiation hardness testing of proof-of-technology prototypes. Plans and a timeline for the fabrication and evaluation of dedicated prototypes are presented.

On behalf of ACFA-IR subgroup, recent activities of our group are reported. A beam halo was estimated by gas scattering through main linac and final focus(FF) system. A compact FF-optics was evaluated by SAD program and designs of warm and superconducting FF quadrupole magnets were updated since the JLC-1 green book. An iron structure was optimized for the detector-solenoid at higher magnetic field of B=3 Tesla. Analyses on the support system of final doublet have been completed for both cases of single support tube and two cantilevers, then the prototype will be constructed in this year. Performances of luminosity monitor and active mask were demonstrated with an emphasis on the fine segmentation in azimuthal angles by Monte Carlo simulations. A new masking system was proposed for the B=3 Tesla. Finally, the beam extraction line was designed with capabilities of measuring energy distribution and polarization, and neutron background was also estimated.

We give a very brief reasoning for the importance of the inclusion of compatible e⁺e⁻ and e⁻e⁻ capabilities for the initial states of Linear Collider experimentation. We also delineate the ease with which this can be accomplished for the existing Linear Electron Collider designs.

An elastic model for double-stranded biopolymers is constructed to study the recently observed DNA entropic elasticity, cooperative extensibility, and super-coiling property. With the introduction of a new structural parameter (the folding angle), bending deformations of sugar-phosphate backbones, steric effects of nucleotide base pairs, and base-stacking interactions are considered to derive the equation governing the evolution of the Green function, which determines the probability distribution of the deformations. By numerically solving this equation we find a comprehensive agreement between theory and experiments in the force-extension relation of DNA and th base-stacking interaction is believed to dominate its elasticity. With the model the deformation of a supercoiled DNA is also studied by Metropolis Monte Carlo simulation and shows the same striking coincidence between theoretical prediction and experimental observations of Strick et al. (Science 271 (1996) 1835; Biophys. J. 74 (1998) 2016).

Molière theory of multiple Coulomb scattering process is reconstructed by use of Kamata-Nishimura formulation of the theory. The latter can be regarded as a thorough extension of Fermi-Yang scattering theory. Traditional angular and lateral distributions under the fixed energy condition are reobtained, moreover the angular distribution is improved to take account ionization loss by the new method. We investigate differences of the result arising from finite rest mass and discuss the unified construction of multiple scattering theory.

Photonic band structures are investigated on quasi-two-dimensional (quasi-2D) photonic crystals made of hexagonally close-packed monolayers of submicron polystyrene microparticles (latex). Experimental dispersion curves for the photonic Bloch modes were obtained from angle-dependent polarized transmission spectra. The results are in fairly good agreement with the theoretical results. Several characteristic features of photonic bands in quasi-2D photonic crystals are demonstrated.

We derive typical phase diagrams for aqueous solutions of different molecular weight methylcellulose (MC) by micro-differential scanning calorimetry, small angle X-ray scattering, and visual inspection. The phase diagrams show co-occurrence of gelation and phase separation, and qualitatively agree with the theoretically calculated ones. The sol-gel transition line and phase separation line of LCST type shift toward lower temperature and lower concentrations with increase in the MC molecular weight. It is observed that the sol-gel transition line intersects at a temperature higher than the critical point of the phase separation, and therefore, both sol-gel phase separation and gel-gel phase separation are possible depending on the temperature. Specifically, by visual inspection of high molecular weight MC sample in the critical temperature region, we observe phase separation into two coexisting gels with different polymer concentration.

The general framework of hypertron and antihypertron structure is obtained by hypertransor analysis. The confinement of nuclei is restricted by the hypertranscendental homotopy linkage.

Developing countries emphasize expansion of the educated population but demand for quality improvement follows later. Current science education reform is driven in part by post cold war restructuring of the global economy and associated focus on the education of a more scientifically literate society, due to the industrial change from labor-intensive to high-technology type, and the societal change inherent in the present information era. Industry needs employees of broad and flexible background with inter disciplinary training, engineers with better physics training, and well trained physicists. Education researches have proved that active-learning based methods are superior to the traditional methods and the information technology (IT) has lot to offer in this. Use of IT for improving physics education is briefly discussed with prospects for collaboration in the Asia-Pacific region via Asian Physics Education Network (ASPEN), UNESCO University Foundation Course in Physics (UUFCP), etc.

A scanning Hall probe microscope (RT-SHPM) incorporating an ultra-high sensitive 0.8 μm GaAs Hall probe sensor was used for imaging magnetic domains at room temperature. Images showed (a) well-defined magnetic transitions in floppy disks to coalesce into small islands under perpendicular external fields and (b) the configurational hysteresis of domain structures in low-coercivity Bi-substituted iron garnet epilayers in alternating external fields. The RT-SHPM was also used for quantitatively imaging ZIP and magneto-optical disk media.

Effects of La composition on para- to ferroelectric phase transition characteristics have been studied in Pb_1−xLa_xTiO₃ ceramics. The phase transition temperature T_c decreases monotonically with decreasing tetragonality c/a. The relative permittivity – temperature characteristics above T_c follow the modified Curie-Weiss law which takes a Gaussian distribution of T_c into account. The deviation δ of the Gaussian distribution decreases with decreasing c/a; this tendency is explained in terms of internal stresses introduced through the phase transition and/or associated with grain size as well as local fluctuations of La composition.

Crystal originated “particle” (COP) on (100) silicon wafer surface was analyzed by Atomic Force Microscopy (AFM). The AFM analyzed COP was pyramidal pit mostly originated from twin octahedral voids surrounded by side walls in {111} planes. The appearance of COP on the (100) polished silicon wafer surface could be either single, separated or joined twin type and square in shape depends which portion of octahedral voids had been cut across during watering processes. As a result, the measured COP image by AFM might not reflect the shape of the COP or in the worst case, the AFM tip shape is misinterpreted as the COP shape. Hence, the side wall angle of COP image obtained by AFM is used to differentiate between actual COP or tip shape. If the side wall angle is comparable to the maximum measurable slope angle of tip, the tip shape is obtained instead of true COP shape. However, if the side wall angle is 55° or below with respect to (100) plane, the AFM image reflect the true COP shape.

The phototransferred thermoluminescence (PTTL) of KCl:Eu²⁺ crystals was studied after exposure to X -rays or β radiation. The main thermoluminescence (TL) peaks were found around 370, 390 and 470 K. The 470 K highest intensity peak is considered to be the dosimetric peak due to its low fading and linear dose behavior. The main dosimetric peak is sharply decreased after illumination with UV light of a previously irradiated specimen. The PTTL is wavelength dependent and has been shown to peak in the 220 - 230 nm region and 650 nm in previously non irradiated and irradiated samples, respectively. The PTTL spectral response is always a broad band around 390 - 490 nm peaked at 425 nm, which is related to the well-known Eu²⁺ emission.

In this study, Ni/Au (5nm/5nm) was chosen as the current-spreading layer on p-type GaN. Sample annealed at 500°C for 10 minutes exhibited the ohmic behavior with a lowest specific contact resistance of 2.0×10⁻² Ω-cm² and a highest transmittance of 78%. The relationship between electronic properties and microstructure of the metal/GaN contacts was also reported.

Lithium doped ZnO films prepared by atmospheric pressure CVD using zinc acetylacetonate (Zn(C₅H₇O₂)₂) and oxygen exhibited a good photoconductivity for near UV light. The films were deposited on glass substrates at 475°C. Lithium dipivaloylmethanato was used as dopant source. The light from a high-pressure Hg lamp with a band-pass filter from 350 to 425 nm was used as the light source. The photosensitivity critically depends on the sublimation temperature (Tc) of the dopant material. The highest photo-to-dark conductivity ratio of 3.71 × 10² was attained for the film deposited at Tc of 183°C. The dark conductivity was 2.69 × 10⁻⁷(S/cm) and rise as well as decay photoresponse was very quick.

The dynamics of photogeneration and pair annihilation of nonequilibrium quasi-particles (photon→A+B→0) in a disordered one-dimensional lattice is examined by numerical simulation. To investigate the nature of the nonequilibrium kinetics of polarons in linear chain materials, the calculation is carried out assuming that every lattice point of randomly disordered lattice can accommodate arbitrary number of particles of the same species. We discuss the time evolution of self-formation of domains during optical pumping and of their decay after discontinuation of pumping.

A superconducting tokamak called KSTAR. is now under construction at the Korea Basic Science Institute in Korea. The KSTAR will be operated in 2004 with Electron Cyclotron Heating (ECH) for pre-ionization and start-up assist. The ECH pre-ionization provides a lower loop voltage and a robust start-up condition for initial discharges. We also plan to increase power, frequency, and operation time from 2 to 300 sees for current drive experiments in upgrade phases. On the other hand, the Lower-Hybrid Current Drive (LHCD) system is under preparation for the effective current drive and off-axis profile control by 2006 in collaboration with the Princeton Plasma Physics Laboratory.

The spectral and laser dynamics of dye laser emissions from low-Q micro-cavities are investigated theoretically and experimentally. The obtained results demonstrate that the ultrashort pulse generation with micro-cavity dye lasers is achieved by some simple ways such as cavity transient, spectro-temporal selection and extra-cavity pulse treatment with saturated dye media.

Organically Modified Silicate (ORMOSIL) materials doped with organic dyes (Rhodamine 6G, Rhodamine B) have been prepared from sol-gel derived using Methyltrimethoxysilane (MTMS) as precursor. The synthesis process was investigated step by step using Raman spectroscopy, and the experimental results demonstrated that Methyl group bounds to silica oxide network remain in the final materials. Broadband laser emission of the materials has been obtained using 532 nm pump pulses from the second harmonic of a Q-switched Nd:YAG laser.

The quasi optical gyrotron is being developed in cooperation between Fukui University and National Institute for Fusion Science. It is a frequency tunable, high power millimeter wave source for plasma diagnostics of LHD. The present status of the gyrotron is described. Gyrotron FU series has been developed at Fukui University and applied to scattering measurement of CHS plasma. The results are also demonstrated briefly.

The physical properties like ultrasonic velocity, density and refractive index has been measured for the binary mixture of Carbon Tetrachloride and Toluene at different temperatures (20°C-50°C). Parameters like isentropic compressibility (K_s), acoustic impedance (Z) and Rao-number (R) are also computed. It was observed that all parameters vary linearly with temperature within the range of concentration and temperature.

The thermal properties of BaFX (X=Cl, Br) crystals by classical molecular dynamics simulation have been examined using the Born-Mayer-Huggins potential. The c/a ratio, density, and the linear thermal expansion coefficients along the directions parallel (α_∥) and perpendicular (α_⊥) to the tetragonal axis have been calculated from the temperature dependence of the lattice parameters (a and c). It was found that both α _∥ and α _⊥ are of the order of (1.0 − 2.0) × 10⁻⁵ K⁻¹ for the bulk BaFBr and (2.5 − 3.5) × 10⁻⁵ K⁻¹ for the bulk BaFCl in the temperature range of 300 and 900 K, and show a change of curvature around 500 K. The present method has also been extended to the bulk BaF₂ and NaCl for the sake of comparison and confirmation.

Composite oxide Sn(y) O_x made by thermal oxidation of the Sn(y)-bimetal thin films, in which y is the doped-materials as well as Sb, Ag or Pd. The Sn(y)–bimetal thin films have been made by evaporation in high vacuum onto NaCl–monocrystall and optical glass substrates. In the work the tin and the doped material (y) were put on two different boats and then both the boats were simultaniously heated to evaporate. The Sn(y)O_x thin films were annealed at the differential temperatures. The structural changes of its have been investigated by using X-ray diffraction and transmission electron microscope.

Ultrasonic longitudinal and shear attenuation measurements was performed at 5-10 MHz in superconducting GdBaSrCu₃O_7−δ between 80 K and 285 K. Longitudinal attenuation profiles showed a large peak around 215 K for low-temperature annealed GdBaSrCu₃O_7−δ but not for quenched GdBaSrCu₃O_7−δ. A smaller peak was also observed at the same temperature for high-temperature annealed GdBaSrCu₃O_7−δ. It is suggested that the differences in the attenuation profiles are due to oxygen O(4) and O(5) ordering involving Cu-O chains of the materials.

Magnesium modified lead titanate (PMT) thin film pyroelectric infrared (IR) detectors were fabricated on Pt(III)/SiO₂/Si(100) substrates using a diol-based sol-gel process. The randomly oriented PMT thin film without the poling treatment exhibits a relatively small dielectric constant and a large pyroelectric coefficient. The pyroelectric properties of PMT thin film point detectors with various Mg contents on modulation frequency are measured and compared. The voltage responsivities (Rv) measured at 20 Hz increase from 1463 to 5280 V/W and the specific detecivities (D^*) measured at 100 Hz increase from 2.44×10⁷ to 5.12×10⁷ cmHz^1/2/W with an increase of Mg content from 0 to 6 mol%. However, the voltage responsivity and the specific detecivity decrease with Mg content in excess of 6 mol%. The results showed that Pb_1−xMg_xTiO₃ thin film with x = 0.06 [PMT(6)] was most suitable for the application of pyroelectric thin film IR detector.

We study the effective pairing mediated by O-ion vibration in the high-T_c oxide superconductor, taking into account two-dimensional screening by the carriers in the CuO₂-conducting layers. The effective attractive interaction due to the strong electron-phonon coupling may dominate the one-site repulsion if the latter is strong. The transition temperature T_c is estimated for different pairing symmetries.

We study a periodic Anderson model with correlated conduction electrons which are described by a Hubbard interaction of strength U within the mean field slave boson theory. The Kondo energy E_k shows a complicated dependence on the interaction U and the conduction band filling. For intermediate interaction a non-exponential behavior of the Kondo scale is found.

We study the correlation effect in optics of semiconductor quantum dot taking into account on-site Coulomb repulsion U in both conduction and valence bands. The midgap excitonic states in the energy spectrum due to Kondo effect is discussed. It is shown that in the small U limit the midgap resonance disappears, while in the large U limit it retains and shifts toward higher energy values.

We study the Kondo effect generated by a single magnetic impurity embedded in an ultrasmall metallic grain within variational approach. The Kondo-singlet formation strongly depends on the parity of the number of electrons on the grain. In the odd-parity case the Kondo effect always occurs and there is a crossover from the Kondo regime to a nonmagnetic regime. In the even-parity case the singlet formation occurs only for strong coupling, and there is a crossover from mixed valence to nonmagnetic regime. We also study the single-electron tunneling conductance and the effect of the Kondo-singlet formation on it.

The ferromagnetic-paramagnetic phase transition temperature, T_C, of Nd_0.7Sr_0.3Mn_1−yMg_yO₃ monotonically decreases from -235 K to -180 K with increasing Mg-doping concentration y from 0 to 0.1. Transport measurements show that Mg-doping does not significantly influence the resistivity in the paramagnetic phase in contrast to that in the ferromagnetic phase below T_C. Interestingly, the magnetoresistance ratio near T_C, in applied fields up to 5 T, increases from 180% for y = 0 to 480% for.y = 0.1. The compounds become spin-glass-like insulators with y ≥ 0.2.

A magnetron dc sputtering system is used to deposit La_0.7Sr_0.3MnO₃ films onto quartz and SrTiO₃(001) substrates. The Curie temperature T_c of LSMO films on both substrates is around 365 K. The temperature dependent resistance of the LSMO/STO film exhibits a semiconductor-metal transition at T_p around 365 K, which coincides with the T_t. However, for the LSMO/quartz film, T_p is 210 K. By investigating the surface morphology of the LSMO films on these two substrates, a granular structure was observed for the LSMO/quartz film but not for the LSMO/STO film. It is suggested that the granular structure is crucial to the difference between T_p and T_c.

An optimization of room-temperature magnetostriction was obtained by combining the deposition of novel spring magnet type TbFeCo/Fe multilayers with annealing effects. The low-field magnetostrictive susceptibility χ_λ = 3.6×10⁻²T⁻¹ was achievable at μ₀H_C = 10 mT. This is discussed in terms of the magnetization enhancement, as well as the contribution of the interfacial magnetic anisotropy.

Series of NbTi/Co bilayers, trilayers, and multilayers were fabricated to study the proximity effect. Whether π phase between neighboring superconducting wavefunctions exists in this system was also investigated. Samples were made by dc magnetron sputtering with Co thickness ranging from 0.3 to 50nm and NbTi thickness ranging from 20 to 400 nm. Magnetic properties were measured by SQUID magnetometer and superconducting transition temperature T_c was determined by resistance measurements. With only 0.9 nm of Co in our samples, the Curie temperature is above room temperature. This indicates alloying effect at the interface is limited.

Giant magnetostrictive material (Terfenol-D) has been extensively used in many applications such as actuators and sonar projectors. However, its major disadvantage is the relative high price due to the complication of manufacturing process. A high strain at moderate field can only be obtained with the single crystal or grain oriented polycrystal. In addition, the use of Terfenol-D is limited at high frequencies because its electrical conductivity is as high as metals. Overcoming this problem by using laminated or rolled sheets of Terfenol-D requires expensive techniques due to their brittleness. In this paper, we present studies on the behavior of Terfenol-D rod under dynamic condition in a Tonpilz type transducer. In addition, a Zinc-bonded sample is prepared and measured to compare with that of the bulk material.

This paper presents some reeenl results of a X-ray in situ study of phase formation process and amorphous-to-nanocrystalline transformation in FeCuNbSiB alloy. Measurements were carried out on the diffractometer Siemens-D5000 with high temperature attachment. Our experiments were performed in both isothermal and nonisothermal regimes in argon atmosphere with time periods from a minute to 3 hours and different temperatures ranging from room temperature to 900°C. The X-ray diffraction data were used to determine the amount of crystalline fraction rs temperature and vs time. Both the first amorphous halo and the (110) diffraction peak of the bcc Fe-based solid solution were fitted, after background substruction. by means of the pseudo-voigt function. The grain sizes for even annealing temperature were determined by the X-ray profile analysis and using Bruker Win-Crysize program package. The kinetics of the nanocrystallization process was investigated and the activation energy was estimated. All the obtained results were compared with those of conventional studies.

Cd₂GeSe₄ film was grown using the thermal evaporation. The film have hexagonal structure. The optical energy band gap for Cd₂GeSe₄ film measured at 300 K was about 1.68 eV. Charged carrier dynamical behavior of Cd₂GeSe₄ film was investigated by photoinduced discharge characteristics. The calculated value of the mobility, carrier concentration were 17.28 cm²/Vs, ∼ 2×10²³/cm³, respectively.

Driven disordered Josephson junction arrays (ladders) in magnetic fields are studied using numerical simulations. There appear three characteristic regimes: pinned, plastic flow, and elastic flow regimes. We discuss behaviors of threshold currents of these regimes in comparison with the random-field XY model.

The microstrueture of a series of Si-rich a-Si:C:H films prepared by dc magnetron sputtering at various carbon (and hydrogen) concentrations was studied by infrared absorption, hydrogen effusion and hydrogen/deuterium interdiffusion experiments. All three methods show the presence of compact material up to a carbon concentration of about 25 at.%, i.e. up to a higher carbon concentration than observed for typical plasma-grown a-Si:C:H films. At carbon concentrations exceeding 25 at.%, the material exhibits a void-rich structure attributed to the presence of hydrogen concentrations exceeding about 1.0−1.5 ×10²cm⁻³.

The thermodynamic properties of 1d Hubbard model within the generalized self-consistent field (GSCF) approach are compared with the Bethe–ansatz calculations for all band fillings n in a wide range magnetic field h and coupling strength U. The concentration of coupled pairs n_pair, variation of the binding energy and stability of inhomogenous state with non-zero center-of-mass momentum q(0 ≤ q ≤ π) versus h and temperature are also studied for various n, U/t.

The exact ground-state (GS) properties and critical behavior in 1d Hubbard model with magnetic field h are investigated numerically in the entire parameter space U, h and n. The spin susceptibility at half-filling changes discontinuously as U → 0 and is enhanced by electron repulsion in comparison with that of the non-interacting case. The compressibility decreases with decreasing of n at U < 0 and shows non-monotonous behavior with dramatic increase while U > 0.

The spectral evolutions of broadband nanosecond dye laser emissions in oscillating and non-oscillating laser regimes are investigated by using a system of rate equations extended to multi-wavelengths. It is demonstrated that in both cases of these laser regimes, a similar process of spectral evolution occurs but at different rates and that the spectral evolution depends not only on dye molecular parameters but also on cavity and pumping parameters. Spectral sweeping in the laser emissions can be controlled by appropriate choice of parameters. This is used to generate picosecond laser pulses adjustable over the 350 nm – 800 nm spectral range.

Optoelectronic signals in laser transmitter modules based on the voltage saturation effect of laser diode have been experimentally studied for the GaAlAs/GaAs (λ = 830 nm) and InGaAsP/InP (λ= 1310 nm) structures. The behavior of the observed optoelectronic signals has been explained as the changing of the relative position of carrier quazi-Fermi levels. The experimental method for definition of the density inversion threshold in the active region of laser diodes has been established as well as the active region internal gain has been measured. These results give the possibility of using laser transmitter modules at the same time as an amplifier and optical switch.

We studied on condensates of a circular and a linear plasmid pUC19 DNA with spermidine in view of reaction time. DNA-spermidine condensates were produced by mixture of 2μl of 5μg/ml DNA solution with 2μl of 0.5mM spermidine aqueous solution. Reaction time is the time elapsed until the mixture is dropped on mica substrate to be imaged with a tapping mode AFM. The reaction times are 30, 15 and 1min. The intermediate progress of DNA-spermidine condensation was found from AFM images dependent on the reaction time.

Land, air and water pollution are the main concerns or current issues in relations to degraded environmental condition which has threatened the quality or of the existence of lives on the earth. Radiation problem brought by the use of atomic energy, loss in ozone layer, green house effect, deforestation etc. are the results of development. Safa Tempo is an electric vehicle operated by 72 V capacity rechargeable lead acid battery. Below 80% discharge of the battery causes shortening of its life. After the replacement of Vickram Tempo (operated by diesel) by Safa Tampo, the pollutant matters have been found to reduce.

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