Chinese Physics B

Zhang, Minhao; Li, Yan; Song, Fengqi; Wang, Xuefeng; Zhang, Rong

doi: 10.1088/1674-1056/26/12/127305pmid: N/A

Quantum phase transition in topological insulators has drawn heightened attention in condensed matter physics and future device applications. Here we report the magnetotransport properties of single crystalline (Bi0.92In0.08)2Se3. The average mobility of is obtained from the Lorentz law at the low field () up to 50 K. The quantum oscillations rise at a field of , revealing a high mobility of at 2 K. The Dirac surface state is evident by the nontrivial Berry phase in the Landau–Fan diagram. The properties make the (Bi0.92In0.08)2Se3 a promising platform for the investigation of quantum phase transition in topological insulators.

Xu, Tao; Chen, Yong; Lin, Ji

doi: 10.1088/1674-1056/26/12/120201pmid: N/A

We investigate some novel localized waves on the plane wave background in the coupled cubic–quintic nonlinear Schrödinger (CCQNLS) equations through the generalized Darboux transformation (DT). A special vector solution of the Lax pair of the CCQNLS system is elaborately constructed, based on the vector solution, various types of higherorder localized wave solutions of the CCQNLS system are constructed via the generalized DT. These abundant and novel localized waves constructed in the CCQNLS system include higher-order rogue waves, higher-order rogues interacting with multi-soliton or multi-breather separately. The first- and second-order semi-rational localized waves including several free parameters are mainly discussed: (i) the semi-rational solutions degenerate to the first- and second-order vector rogue wave solutions; (ii) hybrid solutions between a first-order rogue wave and a dark or bright soliton, a second-order rogue wave and two dark or bright solitons; (iii) hybrid solutions between a first-order rogue wave and a breather, a second-order rogue wave and two breathers. Some interesting and appealing dynamic properties of these types of localized waves are demonstrated, for example, these nonlinear waves merge with each other markedly by increasing the absolute value of α. These results further uncover some striking dynamic structures in the CCQNLS system.

Zhong, Rui; Hou, Qing; Ma, Chao-Qiong; Fu, Bao-Qin; Wang, Jun

doi: 10.1088/1674-1056/26/12/120202pmid: N/A

Molecular dynamics simulations are conducted to study self-interstitial migration in zirconium. By defining crystal lattice points where more than one atom is present in corresponding Wigner–Seitz cells, as the locations of self-interstitial atoms (LSIAs), three types of events are identified as LSIA migrations: the jump remaining in one direction (ILJ), the jump from one to another direction in the same basal plane (OLJ), and the jump from one basal plane to an adjacent basal plane (OPJ). The occurrence frequencies of the three types are calculated. ILJ is found to be a dominant event in a temperature range from 300 K to 1200 K, but the occurrence frequencies of OLJ and OPJ increase with temperature increasing. The total occurrence frequency of all jump types has a good linear dependence on temperature. Moreover, the migration trajectories of LSIAs in the hcp basal-plane is not what is observed if only conventional one- or two-dimensional migrations exists; rather, they exhibit the feature that we call fraction-dimensional. Using Monte Carlo simulations, the potential kinetic effects of fraction-dimensional migration, which is measured by the average number of lattice sites visited per jump event (denoted by nSPE), are analysed. The significant differences between the nSPE value of the fraction-dimensional migration and those of conventional one- and two-dimensional migrations suggest that the conventional diffusion coefficient cannot give an accurate description of the underlying kinetics of SIAs in Zr. This conclusion could be generally meaningful for the cases where the low-dimensional migration of defects are observed.

Du, Chuan-Xun; Meng, Xiang-Guo; Zhang, Ran; Wang, Ji-Suo

doi: 10.1088/1674-1056/26/12/120301pmid: N/A

We investigate how displaced thermal states (DTSs) evolve in a laser channel. Remarkably, the initial DTS, an example of a mixed state, still remains mixed and thermal. At long times, they finally decay to a highly classical thermal field only related to the laser parameters κ and g. The normal ordering product of density operator of the DTS in the laser channel leads to obtaining the analytical time-evolution expressions of the photon number, Wigner function, and von Neumann entropy. Also, some interesting results are presented via numerically investigating these explicit time-dependent expressions.

Liu, Kang; Li, Jian; Zhu, Jian-Rong; Zhang, Chun-Mei; Wang, Qin

doi: 10.1088/1674-1056/26/12/120302pmid: N/A

Reference-frame-independent quantum key distribution (RFI QKD) can generate secret keys without the alignment of reference frames, which is very robust in real-life implementations of QKD systems. However, the performance of decoy-state RFI QKD with both source errors and statistical fluctuations is still missing until now. In this paper, we investigate the performance of decoy-state RFI QKD in practical scenarios with two kinds of light sources, the heralded single photon source (HSPS) and the weak coherent source (WCS), and also give clear comparison results of decoy-state RFI QKD with WCS and HSPS. Simulation results show that the secret key rates of decoy-state RFI QKD with WCS are higher than those with HSPS in short distance range, but the secret key rates of RFI QKD with HSPS outperform those with WCS in long distance range.

Shi, Xian

doi: 10.1088/1674-1056/26/12/120303pmid: N/A

Monogamy is a fundamental property of multi-partite entangled states. Recently, Kim J S [Phys. Rev. A 93 032331] showed that a partially coherent superposition (PCS) of a generalized W-class state and the vacuum saturates the strong monogamy inequality proposed by Regula B et al. [Phys. Rev. Lett. 113 110501] in terms of squared convex roof extended negativity; and this fact may present that this class of states are good candidates for studying the monogamy of entanglement. Hence in this paper, we will investigate the monogamy relations for the PCS states. We first present some properties of the PCS states that are useful for providing our main theorems. Then we present several monogamy inequalities for the PCS states in terms of some entanglement measures.

Qiao, Lei; Chi, Cheng

doi: 10.1088/1674-1056/26/12/120304pmid: N/A

We study the properties of superfluid in a two-dimensional (2D) polarized Fermi gas with spin–orbit coupling and adiabatic rotation which are trapped in a harmonic potential. Due to the competition between polarization, spin–orbit coupling, and adiabatic rotation, the Fermi gas exhibits many intriguing phenomena. By using the Bardeen–Cooper– Schrieffer (BCS) mean-field method with local density approximation, we investigate the dependence of order parameter solution on the spin–orbit coupling strength and the rotation velocity. The energy spectra with different rotation velocities are studied in detail. Besides, the conditions for the zero-energy Majorana fermions in topological superfluid phase to be observed are obtained. By investigating distributions of number density, we find that the rotation has opposite effect on the distribution of number density with different spins, which leads to the enhancement of the polarization of Fermi gas. Here, we focus on the region of BCS pairing and ignore the Fulde–Ferrell–Larkin–Ovchinnikov state.

Li, Chun-Biao; Thio, Wesley Joo-Chen; Sprott, Julien Clinton; Zhang, Ruo-Xun; Lu, Tian-Ai

doi: 10.1088/1674-1056/26/12/120501pmid: N/A

Although chaotic signals are considered to have great potential applications in radar and communication engineering, their broadband spectrum makes it difficult to design an applicable amplifier or an attenuator for amplitude conditioning. Moreover, the transformation between a unipolar signal and a bipolar signal is often required. In this paper, a more intelligent hardware implementation based on field programmable analog array (FPAA) is constructed for chaotic systems with complete amplitude control. Firstly, two chaotic systems with complete amplitude control are introduced, one of which has the property of offset boosting with total amplitude control, while the other has offset boosting and a parameter for partial control. Both cases can achieve complete amplitude control including amplitude rescaling and offset boosting. Secondly, linear synchronization is established based on the special structure of chaotic system. Finally, experimental circuits are constructed on an FPAA where the predicted amplitude control is realized through only two independent configurable analog module (CAM) gain values.

Liu, Yan-Fei; Yang, Dong-Dong; Zheng, Hao; Wang, Li-Xin

doi: 10.1088/1674-1056/26/12/120502pmid: N/A

Superlattices in chaotic state can be used as a key part of a true random number generator. The chaotic characteristics of the signal generated in the superlattice are mostly affected by the parameters of the superlattice and the applied voltage, while the latter is easier to adjust. In this paper, the model of the superlattice is first established. Then, based on this model, the chaotic characteristics of the generated signal are studied under different voltages. The results demonstrate that the onset of chaos in the superlattice is typically accompanied by the mergence of multistability, and there are voltage intervals in each of which the generated signal is chaotic.

Liu, Xiang-Shu; Zhao, Li-Chen; Duan, Liang; Yang, Zhan-Ying; Yang, Wen-Li

doi: 10.1088/1674-1056/26/12/120503pmid: N/A

We study localized waves on continuous wave background in an exponential dispersion decreasing fiber with two orthogonal polarization states. We demonstrate that asymmetric W-shaped and M-shaped soliton pulse can be generated from a weak modulation on continuous wave background. The numerical simulation results indicate that the generated asymmetric soliton pulses are robust against small noise or perturbation. In particular, the asymmetric degree of the asymmetric soliton pulse can be effectively controlled by changing the relative frequency of the two components. This character can be used to generate other nonlinear localized waves, such as dark–antidark and antidark–dark soliton pulse pair, symmetric W-shaped and M-shaped soliton pulse. Furthermore, we find that the asymmetric soliton pulse possesses an asymmetric discontinuous spectrum.