Modern Physics Letters B

The relationship of an asymmetrical Gaussian potential among average number of optical phonons N, temperature T and slab thickness d, in a polar slab was investigated using linear combination operator and unitary transformation methods. The results showed that the phonon frequency $\omega$ increases with increased temperature T, but the average number of optical phonons N and temperature T decreases with increased slab thickness d.

We present an ab initio study of surface supported Au–Mn nanowires. Three different substrates are discussed: Cu(110), stepped Cu(111) and Si(001) surface. The emergence of stable antiferromagnetic (AFM) solutions in Au–Mn nanowires was found in all three cases. We found the nonzero magnetic moments of Mn atoms, however, the bulk of manganese is paramagnetic. The critical temperature of the Au–Mn wires is calculated by means of kinetic Monte Carlo simulation. The strong size-effect of the critical temperature is demonstrated.

The persistent luminescence performance of a novel color-tunable Tb${}^{\mathrm{\text{3}}+}$-doped La${}_{\mathrm{\text{3}}}$GaGe${}_{\mathrm{\text{5}}}$O${}_{\mathrm{\text{1}}6}$ phosphor has been modified by oxygen-deficiency control with an aim to explore the strategy to improve the persistent luminescence property. First-principles calculations were combined with thermoluminescence (TL) measurements to evaluate the role of oxygen vacancies in persistent luminescence of La${}_{\mathrm{\text{3}}}$GaGe${}_{\mathrm{\text{5}}}$O${}_{\mathrm{\text{1}}6}$:Tb${}^{\mathrm{\text{3}}+}$ persistent phosphor. Our results show that the oxygen vacancies that act as an electron trap center have a limited contribution to the persistent luminescence. The formation of the ring structure of La${}_{\mathrm{\text{3}}}$GaGe${}_{\mathrm{\text{5}}}$O${}_{\mathrm{\text{1}}6}$ crystal and the resulting localized trap levels are very different from that of other outstanding persistent phosphors, like Sr${}_{\mathrm{\text{2}}}$MgSi${}_{\mathrm{\text{2}}}$O${}_{\mathrm{\text{7}}}$, etc. Such differences are closely related to the inferior performance of La${}_{\mathrm{\text{3}}}$GaGe${}_{\mathrm{\text{5}}}$O${}_{\mathrm{\text{1}}6}$:Tb${}^{\mathrm{\text{3}}+}$ persistent phosphor.

This paper reports on a semiconducting resistor material based on vanadium sesquioxide (V₂O₃) with electrical resistivity and temperature coefficient of resistance (TCR) appropriate for microbolometer applications. In this work, V₂O₃-based semiconducting resistor material was synthesized and electrically characterized. The developed material was prepared by annealing, in O₂ and N₂ atmospheres, a cascaded multilayer structure composed of V₂O₃ (10 nm) and V (5 nm) room temperature sputter coated thin films. The developed 55 nm thin film microbolometer resistor material possessed high temperature sensitivity from 20${}^{\circ }$C to 45${}^{\circ }$C with a TCR of −3.68%/${}^{\circ }$C and room temperature resistivity of 0.57 $\mathrm{\Omega }\cdot \mathrm{\text{cm}}$ for O₂ annealed samples and a TCR of −3.72%/${}^{\circ }$C and room temperature resistivity of 0.72 $\mathrm{\Omega }\cdot \mathrm{\text{cm}}$ for N₂ annealed samples. The surface morphologies of the synthesized thin films were studied using atomic force microscopy showing no significant post-growth annealing effect on the smoothness of the samples surfaces.

DNA condensation by multivalent cations has been extensively studied using single molecule experiment methods. To detect temperature effect on DNA condensation at the single molecule level, a strong correlation model was developed to investigate the behavior of DNA with self-interactions under constant tension. The simulation results are in line with the single molecule experiment that the kinetics of DNA condensation take on discontinuous and stepwise manner regardless of the toroid or rod-like conformation. By incorporating the temperature dependence of DNA persistence length into the strong correlation model, the temperature effect on DNA condensation is identified. The results indicate that condensed DNA conformations at single molecule level become more compact with increasing temperature.

The microinjection is generally performed on commercial microinjection pump using a nitrogen gas-holder as pressure supply. However, the commercial pump has some problems in picoliter-scale injection due to the instability of pressure source, and the success rate varies significantly across different operators. In this paper, a high-precision, pressure-driven pump for sub-picoliter scale quantitative injection is developed. This new pumping system is capable of generating a wide range of positive and negative pressure with high resolution by connecting a buffer tank to the gas passage structure. It is able to generate pressure between −30 kPa and +150 kPa with a resolution less than 1 Pa. Compared to the commercial pump, the new pumping system has high stability and resolution (less than 1 Pa versus 68.9 Pa). The injection accuracy of the system was further proved by applying it to quantitative injection experiment. The results demonstrate that the injection accuracy of the injection volume is 0.0022 pL.

We report, for the first time to our knowledge, the terahertz (THz) spectra of isonicotinic acid and 2-picolinic acid. The distinct THz spectral differences among these two isomers and nicotinic acid have also been observed, indicating that the THz vibrational modes are highly sensitive to the structural differences even in similar molecular crystals. Besides, solid-state density functional theory calculations reveal better qualitative agreement with the measured absorption features, which are related to the molecular vibrations of nicotinic acid and isonicotinic acid. As for 2-picolinic acid, the calculation based on the primitive cell reproduces the absorption features at 1.46, 1.82 and 2.46 THz originating from intermolecular vibrations. These results suggest that THz spectra can identify the complex intermolecular interactions even in similar molecular crystals, which shows potential applications in identifying isomers in food and pharmaceutical production.

A semi-quantum secret sharing (SQSS) scheme based on Bell states is proposed in this paper. The sender who can perform any relevant quantum operations uses Bell states to share the secret keys with her participants that are limited to perform classical operations on the transmitted qubits. It is found that our scheme is easy to generalize from three parties to multiparty and more efficient than the previous schemes [Q. Li, W. H. Chan and D. Y. Long, Phys. Rev. A 82 (2010) 022303; L. Z. Li, D. W. Qiu and P. Mateus, J. Phys. A: Math. Theor. 26 (2013) 045304; C. Xie, L. Z. Li and D. W. Qiu, Int. J. Theor. Phys. 54 (2015) 3819].

In nature, there exists superposition of Gaussian light and chaotic light, so we introduce the density operator for describing the Gaussian-enhanced chaotic light (GECL). By virtue of the method of integration within ordered product (IWOP) of operators, we derive its normalization constant. Then, by virtue of the partial trace method, we derive its thermo vacuum state and this may greatly simplify the calculation of photon number average and quantum fluctuation in GECL. It is demonstrated that the second-order degree of coherence of GECL is larger than 2.

We present the Gross–Pitaevskii equation for Bose–Einstein condensates (BECs) possessing the electric dipole and the electric quadrupole moments in a non-integral form. These equations are coupled with the Maxwell equations. The model under consideration includes the dipole–dipole, the dipole–quadrupole, and the quadrupole–quadrupole interactions in terms of the electric field created by the dipoles and quadrupoles. We apply this model to obtain the Bogoliubov spectrum for three-dimensional BECs with a repulsive short-range interaction. We obtain an extra term in the Bogoliubov spectrum in comparison with the dipolar BECs. We show that the quadrupole–quadrupole interaction gives a positive contribution in the Bogoliubov spectrum. Hence, this spectrum is stable.