International Journal of Modern Physics B

Measurement-based quantum computing (MBQC) is a model of quantum computing that proceeds by sequential measurements of individual spins in an entangled resource state. However, it remains a challenge to produce efficiently such resource states. Would it be possible to generate these states by simply cooling a quantum many-body system to its ground state? Cluster states, the canonical resource states for MBQC, do not occur naturally as unique ground states of physical systems. This inherent hurdle has led to a significant effort to identify alternative resource states that appear as ground states in spin lattices. Recently, some interesting candidates have been identified with various valence-bond-solid (VBS) states. In this review, we provide a pedagogical introduction to recent progress regarding MBQC with VBS states as possible resource states. This study has led to an interesting interdisciplinary research area at the interface of quantum information science and condensed matter physics.

In this paper, we study the preparation of titanate/polypyrrole core-shell rod-like composite particles. The mere titanate rod-like particles were prepared as core material and PPy was polymerized on their surface in different amounts. Rheological measurements showed that under an applied external electric field, shear stress of these materials significantly increased with amount of PPy in the shell layer. The yield stresses obtained from the Cho-Choi-Jhon model were correlated with dielectric properties of suspensions. Polarizability as a measure of particle polarization obtained from Havriliak–Negami model of dielectric spectra increases with the content of PPy in the samples. Furthermore, role of particle concentration and silicone oil viscosity was also investigated.

The research results of photoelectric, optical and recombination properties of neutron transmutation doped (NTD) semiconductor solid alloys Si_1-xGe_x(x = 0.008–0.112) are presented in spectral range 0.8–10.6 μm. It is shown that these properties of NTD Si_1-xGe_x are determined by creation of transmutation impurities of Se and Ga as well as by variation of Ge content and compensation. The theoretical and applied aspects of the NTD Si_1-xGe_x have been also considered.

In the present work, a method to impose the inextensibility constraints on the dynamics of a chain fluctuating in a thermal bath at fixed temperature is investigated. The final goal is to construct the probability function of the chain and the generating functional of the correlation functions of the relevant degrees of freedom of the system. First, we study the dynamics of a freely hinged chain composed by massive beads connected together by massless segments of fixed length. It is shown that a system of this kind may be described by a set of Langevin equations in which the noise is characterized by a non-gaussian probability distribution. Starting from these Langevin equations, the generating functional of the freely hinged chain is derived in path integral form. A connection with a stochastic process governed by a Fokker–Planck equation is established. Next, a chain composed by one-dimensional bars with constant mass distribution is considered. A path integral expression of the generating functional for a chain of this type is derived. Finally, it is verified that in the limit in which the chain becomes continuous, both generating functionals of the freely hinged chain and of the freely jointed bar chain converge to the same result as expected.

Amorphous zirconium oxide (a-ZrO₂) thin films were prepared onto fuzzed quartz substrates by ion beam sputtering deposition (IBSD) method in (Ar +O₂) gas mixture. Optical parameters of the films were evaluated by laser ellipsometry (λ = 632.8 nm) and optical transmission measurements. Structural parameters were studied by XRD measurements. Variation of refractive index and film thickness have been defined as a function of time of high-temperature annealing at T = 900°C. Formation of monoclinic zirconium oxide (m-ZrO₂) nanocrystals with diameter of ~60 nm embedded into a-ZrO₂ matrix has been found by XRD analysis after long-time annealing.

The change in thermodynamic quantities (e.g., entropy, specific heat etc.) by the application of magnetic field in the case of the high-T_c superconductor YBCO system is examined phenomenological by the Ginzburg–Landau theory of anisotropic type-II superconductors. An expression for the change in the entropy (ΔS) and change in specific heat (ΔC) in a magnetic field for any general orientation of an applied magnetic field B_a with respect to the crystallographic c-axis is obtained. The observed large reduction of specific heat anomaly just below the superconducting transition and the observed variation of entropy with magnetic field are explained quantitatively.