**Unambiguous discrimination of nonorthogonal entangled quantum states in cavity QED**

Publication date: Available online 10 July 2019Source: Physics Letters AAuthor(s): R.J. de Assis, J.S. Sales, N.G. de AlmeidaAbstractIn this work we propose a scheme in the context of superconducting cavities to unambiguously discriminate non-orthogonal quantum field states when one of them is one of the four Bell states. The present work, which generalizes an earlier proposal [1] dealing with non-entangled states, also makes use of a single high Q cavity, a sample of three-level atoms, Ramsey zones and selective detectors, thus consisting of an oversimplification from the experimental view. (Source: Physics Letters A)

**Source: **Physics Letters A - July 12, 2019 **Category: **Physics **Source Type: **research

**GPU-based DPSO algorithm for structural optimization of Pt-Co bimetallic nanoparticles**

Publication date: Available online 10 July 2019Source: Physics Letters AAuthor(s): Gui-Fang Shao, Jian-Bo Yang, Jun-Fa Zhang, Tun-Dong Liu, Yu-Hua WenAbstractAlloy nanoparticles (NPs) are potential candidates for catalysts in fuel cells applications, and their physical properties are associated with the corresponding stable structures. In this work, a GPU-based discrete particle swarm optimization (DPSO) method is designed to investigate the stable structure of Pt-Co alloy NPs. Register and an optimal block design are used to further increase the acceleration ratio. Comparative experiments on CPU and GPU show that the GPU-...

**Source: **Physics Letters A - July 12, 2019 **Category: **Physics **Source Type: **research

**Nonlinear bandgap properties in a nonlocal piezoelectric phononic crystal nanobeam**

Publication date: Available online 9 July 2019Source: Physics Letters AAuthor(s): Denghui Qian, Zhiyu Shi, Chengwei Ning, Jianchun WangAbstractApplying nonlocal elasticity theory, von Kármán type nonlinear strain-displacement relation and plane wave expansion (PWE) method to Euler-Bernoulli beam, the calculation method of band structure of a nonlinear nonlocal piezoelectric phononic crystal (PC) nanobeam is proposed and formulized. In order to investigate the properties of wave propagating in the nanobeam in detail, band gaps of first four orders are picked, and the corresponding influence rules of electro-me...

**Source: **Physics Letters A - July 10, 2019 **Category: **Physics **Source Type: **research

**Temperature-dependent XAFS study of the local lattice distortion of the CuO2 plane in Sr2CuO3+δ powder sample**

Publication date: Available online 9 July 2019Source: Physics Letters AAuthor(s): Haibo Wang, Ying Liu, Zhenlin Luo, Qingqing Liu, Yuanjun Yang, Haoliang Huang, Mengmeng Yang, Changqing Jin, Chen GaoAbstractIn order to study the relationship between local lattice distortion and superconductivity, we performed temperature dependent x-ray absorption fine structure (XAFS) on Sr2CuO3+δ powder sample (single phase with Tc=48 K). The temperature dependent Debye-Waller factor of Cu-O pair appears an anomalous upturn at 90 K and becomes drop around the superconducting transition temperature of ∼50 K. It means that local ...

**Source: **Physics Letters A - July 10, 2019 **Category: **Physics **Source Type: **research

**Characterization of a Planar NID Chiral Interface under Negative and/or Positive Phase Velocity Conditions**

Publication date: Available online 8 July 2019Source: Physics Letters AAuthor(s): Samra Kanwal, Qaisar Abbas NaqviAbstractUsing positive and/or negative phase velocity conditions, characteristics of a planar non-integer dimensional (NID) chiral interface are explored for specific values of NID parameter. For this purpose, discussion is divided into four cases. It is noted how characteristics of the interface changes when the situation is changed from one case to another. Impact of variation of NID parameter on the reflected power is also noted for each case. (Source: Physics Letters A)

**Source: **Physics Letters A - July 9, 2019 **Category: **Physics **Source Type: **research

**Nanophotonic on-chip hybrid plasmonic electro-optic modulator with phase change materials**

Publication date: Available online 8 July 2019Source: Physics Letters AAuthor(s): Mandeep Singh, Sanjeev Kumar Raghuwanshi, T. SrinivasAbstractA vertical hybrid plasmonic waveguide (HPWG) modulator incorporating Au nano-rings and operating in the near-infrared (NIR) band is proposed using phase change chalcogenide thin film (Ge2Sb2Te5, commonly known as GST). It is shown that with amorphous to crystalline phase transition of GST, significant modulation depths can be achieved in the optical C-band. Further, localized surface plasmon resonance (LSPR) excitations from the Au nano-ring embedded in the low-indexed slot region i...

**Source: **Physics Letters A - July 9, 2019 **Category: **Physics **Source Type: **research

**Spin and spin-valley Hall effects in a honeycomb lattice with antiferromagnetism and spin-orbit couplings**

Publication date: Available online 8 July 2019Source: Physics Letters AAuthor(s): Jianfei Zou, Yinghan Yuan, Jing KangAbstractWe study linear response to a longitudinal electric field on an antiferromagnetic honeycomb lattice with intrinsic and Rashba spin-orbit couplings (SOCs). It is found that the spin-valley Hall effect could emerge alone or coexist with the spin Hall effect. The spin and spin-valley Hall conductivities exhibit some peculiarities that depend on the distinct topological states of the graphene lattice. Furthermore, the spin and spin-valley Hall conductivities could be remarkably modulated by changing the...

**Source: **Physics Letters A - July 9, 2019 **Category: **Physics **Source Type: **research

**Higher-order solutions of a matrix AKNS system associated with a Hermitian symmetric space**

Publication date: Available online 8 July 2019Source: Physics Letters AAuthor(s): Xianguo Geng, Jing Shen, Bo XueAbstractIn this paper, we study a matrix Ablowitz–Kaup–Newell–Segur (AKNS) system associated with a Hermitian symmetric space as a follow-up study of an earlier paper. A multi-fold generalized Darboux transformation of the matrix AKNS system associated with a Hermitian symmetric space is constructed by means of determinants. Subsequently, we derive various higher-order solutions for this system, including fan-shaped rogue wave and (truncated) Kuznetsov–Ma breather solutions. Specifically,...

**Source: **Physics Letters A - July 9, 2019 **Category: **Physics **Source Type: **research

**Core-shell quantum dot electron bubbles as exotic ions in superfluid liquid 4He**

Publication date: Available online 8 July 2019Source: Physics Letters AAuthor(s): Nabil M. LawandyAbstractA number of experiments in superfluid helium-4 over the past fifty years on the mobility of electron bubbles, which are unique quantum dots in the liquid state, revealed the existence of a “fast” ion and other “exotic” negative ions whose origin and structure still remains unresolved. The fast ion has a mobility which is six times that of the well understood single electron bubble and the other ions span a region from the fast ion mobility to that of the electron bubble. The work presented here ...

**Source: **Physics Letters A - July 9, 2019 **Category: **Physics **Source Type: **research

**Editors**

Publication date: 12 August 2019Source: Physics Letters A, Volume 383, Issue 23Author(s): (Source: Physics Letters A)

**Source: **Physics Letters A - July 9, 2019 **Category: **Physics **Source Type: **research

**Effect of the weak interaction on the in situ radii of condensate boson atoms in one or two-dimensional deep optical lattices**

Publication date: Available online 2 July 2019Source: Physics Letters AAuthor(s): Ahmed S. Hassan, Azza M. El-Badry, Alyaa A. Mahmoud, Hend A. Abdel-Gany, Adel M. Mohammedein, A.M. AbdallahAbstractIn this letter we suggest a theoretical model to investigate the weak interaction dependence of the in situ radii of condensate boson atoms in a combined harmonic with one or two-dimensional deep optical lattice. The semiclassical approximation is employed to calculate the above mentioned parameters. The calculated results showed that the in situ radii depends crucially on the interatomic interaction. Our results can be extended ...

**Source: **Physics Letters A - July 9, 2019 **Category: **Physics **Source Type: **research

**Anisotropic Keldysh interaction**

Publication date: Available online 5 July 2019Source: Physics Letters AAuthor(s): Andrei GaliautdinovAbstractWe generalize the classic calculations by Rytova and Keldysh of screened Coulomb interaction in semiconductor thin films to systems with anisotropic permittivity tensor. Explicit asymptotic expressions for electrostatic potential energy of interaction in the weakly anisotropic case are found in closed analytical form. The case of strong in-plane anisotropy, however, requires evaluation of the inverse Fourier transform of 1/(k+Akx2+Bky2), which, at present, remains unresolved. (Source: Physics Letters A)

**Source: **Physics Letters A - July 7, 2019 **Category: **Physics **Source Type: **research

**Stability boundaries of a Mathieu equation having PT symmetry**

Publication date: Available online 4 July 2019Source: Physics Letters AAuthor(s): P.A. BrandãoAbstractI have applied multiple-scale perturbation theory to a generalized complex PT-symmetric Mathieu equation in order to find the stability boundaries between bounded and unbounded solutions. The analysis suggests that the non-Hermitian parameter present in the equation can be used to control the shape and curvature of these boundaries. Although this was suggested earlier by several authors, analytic formulas for the boundary curves were not given. This paper is a first attempt to fill this gap in the theory. (Source: Physics Letters A)

**Source: **Physics Letters A - July 6, 2019 **Category: **Physics **Source Type: **research

**Conductance of inhomogeneous Luttinger liquids with a finite bandwidth**

Publication date: Available online 4 July 2019Source: Physics Letters AAuthor(s): Joy Prakash Das, Girish S. SetlurAbstractThe finite-bandwidth conductance of a Luttinger liquid (LL) with a cluster of impurities is studied and its variation with respect to temperature is shown. The calculations are done using the correlation functions obtained using the powerful non-chiral bosonization technique (NCBT). The results are compared with those obtained by Matveev, Yue and Glazman [K. Matveev et al., Phys. Rev. Lett. 71, 3351 (1993)] who deal with a weakly interacting LL. By contrast, NCBT correctly provides the conductance for ...

**Source: **Physics Letters A - July 6, 2019 **Category: **Physics **Source Type: **research

**Impacts of phase transformation on the thermoelectric properties of ZnO nanowires**

Publication date: Available online 3 July 2019Source: Physics Letters AAuthor(s): Lihong Shi, Jia He, Dengfeng LiAbstractImpacts of phase transformation from regular wurtzite phase to a graphitic polymorph hexagonal phase under tensile loading, on the thermoelectric properties of Zinc oxide nanowires (ZnO NWs), which is oriented in the [0001] direction, are studied by combining the first-principles simulation with one-dimensional (1D) Boltzmann transport equation (BTE). Our results show that this phase transformation has greatly influenced the thermoelectric properties of the ZnO NWs. We also find that the largest value of...

**Source: **Physics Letters A - July 5, 2019 **Category: **Physics **Source Type: **research

**Low bias negative differential resistance with dual-peaks based on octacene molecular device**

Publication date: Available online 3 July 2019Source: Physics Letters AAuthor(s): J. Zhang, Z. Qin, B. Xu, G. SongAbstractBased on non-equilibrium Green's function and density functional theory, a first-principles study of the transport properties of a molecular device is performed. This device is composed of two octacene molecules separated by a ethyl barrier, which are then linked to Ag leads through thiolates. The device shows low bias negative differential resistance effect with dual-peaks, which may be useful for designing molecular devices with low power-dissipation and multi-function in the future. (Source: Physics Letters A)

**Source: **Physics Letters A - July 5, 2019 **Category: **Physics **Source Type: **research

**Phase transitions in normalized cut of social networks**

Publication date: Available online 3 July 2019Source: Physics Letters AAuthor(s): Wei Lin, Min Li, Shuming Zhou, Jiafei Liu, Gaolin Chen, Zhengdong GuAbstractOne of the main goals of network analysis and data science is to identify community structures in a network. Community structure is a typical feature of social networks and community detection is considered to be crucial to understand the structure and function of social networks in cyberspace. The community detection problem of social networks can be viewed as a graph partitioning problem whose objective is to identify the external edges as the edge cut that separate...

**Source: **Physics Letters A - July 5, 2019 **Category: **Physics **Source Type: **research

**The electronic structures and properties for carbon doped aluminum phosphide**

Publication date: Available online 3 July 2019Source: Physics Letters AAuthor(s): S.W. Fan, L. Yang, G.Y. GaoAbstractBased on the first-principle method, the effects of carbon dopants on AlP are studied. Our investigations indicate carbons substituting aluminum (CAl) or phosphorus (CP) cannot induce the AlP to be magnetic system. The AlP with CAl defects shows n-type metallic characteristic. As the carbons forming the interstitial doped configurations (Cint), a few percent of Cint could induct the AlP to be a half-metallic ferromagnet, and the half-metallic gaps could reach 0.45∼0.48 eV. Mean field theory predicts the ...

**Source: **Physics Letters A - July 5, 2019 **Category: **Physics **Source Type: **research

**Approximate bound state solutions of the Klein-Gordon equation with the linear combination of Hulthén and Yukawa potentials**

Publication date: Available online 2 July 2019Source: Physics Letters AAuthor(s): A.I. Ahmadov, S.M. Aslanova, M.Sh. Orujova, S.V. Badalov, Shi-Hai DongAbstractBased on a developed scheme we show how to deal with the centrifugal term and the Coulombic behavior part and then to solve the Klein-Gordon (KG) equation for the linear combination of Hulthén and Yukawa potentials. Two cases, i.e., the scalar potential which is equal and unequal to vector potential, are considered for arbitrary l state. With the aid of the Nikiforov-Uvarov (NU) method and the traditional approach, we present the eigenvalues and the correspon...

**Source: **Physics Letters A - July 3, 2019 **Category: **Physics **Source Type: **research

**Effect of the weak interaction on the in situ radii of condensate boson atoms in one and two deep optical lattices**

Publication date: Available online 2 July 2019Source: Physics Letters AAuthor(s): Ahmed S. Hassan, Azza M. El-Badry, Alyaa A.Mahmoud, Hend A. Abdel-Gany, Adel M. Mohammedein, A.M. AbdallahAbstractIn this letter we suggest a theoretical model to investigate the weak interaction dependence of the in situ radii of condensate boson atoms in a combined harmonic one and two dimensions deep optical lattice. The semiclassical approximation is employed to calculate the above mentioned parameters. The calculated results showed that the in situ radii depends crucially on the interatomic interaction. Our results can be extended to inv...

**Source: **Physics Letters A - July 3, 2019 **Category: **Physics **Source Type: **research

**Dynamics and phase transitions in biased ladder systems with magnetic flux**

Publication date: Available online 2 July 2019Source: Physics Letters AAuthor(s): Xin Qiao, Xiao-Bo Zhang, Ai-Xia Zhang, Zi-Fa Yu, Ju-Kui XueAbstractThe ground states and the dynamics of a biased two-leg flux ladder in the presence of a gravitational field are discussed. In the absence of the gravitational field, the ground states and the critical condition of phase transition are obtained analytically. We identify the Meissner phase, Vortex phase, and interestingly, two new Plane Wave phases, that break both Z2 and time-reversal symmetry, characterized by the imbalance particle density distribution, asymmetry double well ...

**Source: **Physics Letters A - July 3, 2019 **Category: **Physics **Source Type: **research

**Transmission coefficient of interacting few-body system in one dimensional space**

We present a novel way of defining transmission coefficient of one spatial dimensional few interacting electrons system. The formalism is based on the probability interpretation of unitarity of physical scattering S-matrix. The relation of our formalism to the well-established method for describing the conducting properties of non-interacting systems, Landauer-Büttiker formula, is discussed. The transport properties of interacting two-electron system is also discussed as a specific example of our formalism. (Source: Physics Letters A)

**Source: **Physics Letters A - July 3, 2019 **Category: **Physics **Source Type: **research

**Thermoelectric coefficient in nanoisland metallic films**

Publication date: Available online 2 July 2019Source: Physics Letters AAuthor(s): A.P. Boltaev, F.A. Pudonin, I.A. Sherstnev, D.A. EgorovAbstractWe study the thermoelectric properties of island metal films on a dielectric substrate. Dependence of thermoelectric coefficient of metal films on their thickness with the dimensionless conductance g>1 and g

**Source: **Physics Letters A - July 3, 2019 **Category: **Physics **Source Type: **research

**Dependence of valley polarization on Schottky metal stripe in magnetic-strain graphene**

This study is very useful for understanding and designing the valleytronic devices. (Source: Physics Letters A)

**Source: **Physics Letters A - July 3, 2019 **Category: **Physics **Source Type: **research

**Chirality, helicity and the rotational content of electromagnetic fields**

Publication date: Available online 2 July 2019Source: Physics Letters AAuthor(s): M. Fernández GuastiAbstractThe chirality continuity equation in the presence of charge and current is obtained from the complementary fields formalism. In the presence of sources, it is strongly suggested that the chirality should be defined proportional to με(H⋅∂tE−E⋅∂tH) instead of the usual definition H⋅(∇×B)+εE⋅(∇×E). Both definitions are equivalent for free fields. The relationship between helicity ϱAC and chirality ϱEH for arbitrary wave solutions is...

**Source: **Physics Letters A - July 3, 2019 **Category: **Physics **Source Type: **research

**Quantum repeated games with continuous-variable strategies**

Publication date: Available online 2 July 2019Source: Physics Letters AAuthor(s): Zhe Yang, Xian ZhangAbstractBy the Li-Du-Massar method, we investigate the quantization of a two-stage repeated duopoly game. By solving the quantum repeated game with continuous-variable strategies, we analyze the effect of two stages' entanglement levels, and give some numerical evidences to describe our model. (Source: Physics Letters A)

**Source: **Physics Letters A - July 3, 2019 **Category: **Physics **Source Type: **research

**Activating MoS2 basal planes for hydrogen evolution through the As doping and strain**

Publication date: Available online 2 July 2019Source: Physics Letters AAuthor(s): Yi-Qi Yang, Chun-Xiang Zhao, Shou-Yan Bai, Cai-Ping Wang, Chun-Yao NiuAbstractAs a non-precious catalyst for the electrochemical hydrogen evolution reaction (HER), the two-dimensional MoS2 has been widely studied. To activate the MoS2 inert basal plane to enable optimal activity, high defect concentration of sulfur vacancies is needed. Herein, based on the first-principles calculations we demonstrate that the HER of MoS2 can be greatly enhanced by As doping and biaxial strain. We show that the As-doping sites are new catalytic sites and the b...

**Source: **Physics Letters A - July 3, 2019 **Category: **Physics **Source Type: **research

**Spin polarized carrier injection driven magneto-optical Kerr effect in Cr-doped ZnO nanorods**

Publication date: Available online 28 June 2019Source: Physics Letters AAuthor(s): M. Malaidurai, B. Santosh Kumar, R. ThangavelAbstractHydrothermal growth of Cr doped ZnO nanorods (NRs) thin films was grown on glass substrates. The strong ferromagnetic (FM) and antiferromagnetic (AFM) ordering was observed in 3% and 7% of Cr doped samples. The optical excitation of the Cr doped ZnO NRs is responsible for injection of the spin-polarized carriers in the 3% Cr doped ZnO NRs through longitudinal magneto-optical Kerr effect (MOKE). We determined a negative anisotropic magnetoresistance (∼23%) originated from spin orbit cou...

**Source: **Physics Letters A - June 30, 2019 **Category: **Physics **Source Type: **research

**Temperature-electric field hysteresis loop of multicaloric effects in PbZr0.8Ti0.2O3 thin films**

Publication date: Available online 28 June 2019Source: Physics Letters AAuthor(s): F. Wang, T. Liu, C.L. Xie, Y. Liu, N.S. Ma, J. Duan, J.R. He, B. Li, B.L. Ou, Y. Ou, J.J. Cheng, Q. Liu, L.F. Liu, W. WangAbstractThe Multicaloric effect in the PbZr0.8Ti0.2O3 thin films is investigated with the application of sine wave electric field, dc electric field and stress using a phase field method combined with the thermodynamic analysis. The simulation results show that the adiabatic temperature change-electric field curve presents a shape of butterfly in the presence of the sine wave electric field. In order to detect the effect ...

**Source: **Physics Letters A - June 30, 2019 **Category: **Physics **Source Type: **research

**Preferred states of open electronic systems**

Publication date: Available online 27 June 2019Source: Physics Letters AAuthor(s): HaoXiang Jiang, Yu ZhangAbstractSystem-environment interaction may introduce dynamic destruction of quantum coherence, resulting in a special representation named as pointer states. In this work, pointer states of an open electronic system are studied. The decoherence effect is taken into account through two different ways which are Büttiker's virtual probe model and strong electron-phonon interaction in the polaron picture. The pointer states of the system with different coupling strength are investigated. The pointer states are identi...

**Source: **Physics Letters A - June 29, 2019 **Category: **Physics **Source Type: **research

**The exact solution for the free induction decay in a quasi-one-dimensional system in a multi-pulse NMR experiment**

Publication date: Available online 27 June 2019Source: Physics Letters AAuthor(s): G.A. Bochkin, E.B. Fel'dman, S.G. Vasil'evAbstractThe exact solution for the free induction decay in a one-dimensional system in the multi-pulse experiment is obtained at both high and low temperatures in the approximation of nearest neighbor interactions. The experimental investigation is performed on a quasi-one-dimensional system of 19F nuclear spins in a single crystal of fluorapatite. The theoretical results are in a good agreement with the obtained experimental data. (Source: Physics Letters A)

**Source: **Physics Letters A - June 29, 2019 **Category: **Physics **Source Type: **research

**Energy band modulation of GaAs/Al0.26Ga0.74As quantum well in 3D self-assembled nanomembranes**

In this study, we investigate the modulation of energy band in 3D self-assembled nanomembranes containing GaAs/Al0.26Ga0.74As quantum wells (QWs). Photoluminescence (PL) characterizations demonstrate that the self-assembled structures have different optical transition properties and the modulation of the energy band is thus realized. Detailed spectral analyses disclose that the small strain change in structures with different curvatures cannot cause remarkable change in energy bands in Al0.26Ga0.74As layer. On the other hand, the optical transitions of GaAs QW layer is influenced by the strain evolution in term of light em...

**Source: **Physics Letters A - June 29, 2019 **Category: **Physics **Source Type: **research

**Numerical investigation of a tunable metamaterial perfect absorber consisting of two-intersecting graphene nanoring arrays**

Publication date: Available online 26 June 2019Source: Physics Letters AAuthor(s): Chunlian Cen, Yubin Zhang, Cuiping Liang, Xifang Chen, Zao Yi, Tao Duan, Yongjian Tang, Xin Ye, Yougen Yi, Shuyuan XiaoAbstractIn this paper, we report a numerical investigation of tunable dual-band metamaterial perfect absorber (MMPA) consisting of two-intersecting graphene nanorings arrays. The optical absorption performance of absorber is dominated by the inner/outer radius of nanorings and center distance between the two nanorings. For the resonance modes λ1 and λ2, the sensitivity of probing the surrounding refractive inde...

**Source: **Physics Letters A - June 27, 2019 **Category: **Physics **Source Type: **research

**Physical meaning of the stretched exponential Kohlrausch function**

Publication date: Available online 26 June 2019Source: Physics Letters AAuthor(s): Alexander LukichevAbstractIn this paper the physical meaning of the empirical Kohlrausch-Williams-Watts (KWW) function is explained in terms of the linear oscillator theory. It is shown that the KWW function is a solution of the non-autonomous linear first order equation for an overdamped linear oscillator. From the linear oscillator model it follows that the KWW-type relaxation is the linear relaxation with a time (coordinate, stress, voltage, etc.) dependent dissipation of energy. The theoretical results are validated by measurements. A me...

**Source: **Physics Letters A - June 27, 2019 **Category: **Physics **Source Type: **research

**Average versus maximal coherence**

Publication date: Available online 21 June 2019Source: Physics Letters AAuthor(s): Shunlong Luo, Yuan SunAbstractCoherence is a fundamental feature of quantum mechanics and plays a crucial role in the quantum realm. The issue of quantification of coherence has received considerable interests in recent years, and a variety of coherence quantifiers have been introduced. With these measures, one can investigate coherence in a more quantitative way. Based on the Wigner-Yanase skew information, we evaluate average coherence of a state with respect to arbitrary mutually unbiased bases as well as with respect to all orthonormal b...

**Source: **Physics Letters A - June 23, 2019 **Category: **Physics **Source Type: **research

**Prediction of two-dimensional monochalcogenides: MoS and WS**

Publication date: Available online 19 June 2019Source: Physics Letters AAuthor(s): Dhanshree Pandey, Aparna ChakrabartiAbstractUsing density functional theory, we explore the possibility of two monolayer monochalcogenides, namely, MoS and WS. From the energetics, buckled and puckered structures are found to be more probable configurations. Our results on cohesive energy and phonon dispersion predict that the buckled structures of both MoS and WS are stable. On the other hand, while the puckered structure of WS clearly shows a dynamical instability, the same for MoS may have a stable configuration. Charge analyses predict i...

**Source: **Physics Letters A - June 20, 2019 **Category: **Physics **Source Type: **research

**Phase role of white TiO2 precursor in its reduction to black TiO2**

Publication date: Available online 19 June 2019Source: Physics Letters AAuthor(s): Haiyang Hu, Yan Lin, Yun Hang HuAbstractBlack TiO2, which is a promising photocatalyst with enhanced visible light absorption, is a new semiconductor with a smaller band gap than white TiO2. The synthesis of black TiO2 has been focused on optimizing hydrogen treatment and exploring different reductants. However, in this work, it was experimentally demonstrated that the phase structure of white TiO2 precursor plays an important role in its reduction to black TiO2 by hydrogen treatment, namely, compared with anatase TiO2, rutile TiO2 is much e...

**Source: **Physics Letters A - June 20, 2019 **Category: **Physics **Source Type: **research

**An improved quantum principal component analysis algorithm based on the quantum singular threshold method**

Publication date: Available online 20 June 2019Source: Physics Letters AAuthor(s): Jie Lin, Wan-Su Bao, Shuo Zhang, Tan Li, Xiang WangAbstractQuantum principal component analysis (qPCA) is a dimensionality reduction algorithm for getting the eigenvectors corresponding to top several eigenvalues of the data matrix and then reconstructing. However, qPCA can only construct the quantum state contains all the eigenvectors and eigenvalues. In this paper, we present an improved quantum principal component analysis (Improved qPCA) algorithm with a fixed threshold. We can reduce the singular value less than the threshold to 0 and o...

**Source: **Physics Letters A - June 20, 2019 **Category: **Physics **Source Type: **research

**Topological nature of Hubbard bands in strongly correlated systems**

Publication date: Available online 18 June 2019Source: Physics Letters AAuthor(s): V.Yu. Irkhin, Yu.N. SkryabinAbstractThe topological nature of the Mott-Hubbard state in strongly correlated systems is treated. These systems are described in terms of spin-charge separation, i.e. spinon-holon deconfinement in the gauge field. Analogies with the quantum Hall effect and Landau quantization are considered, the presence of the Chern-Simons term being important for proper description of the Hubbard splitting. Occurrence of topological frustrations with doping in an effective two-band model is demonstrated. The role of orbital de...

**Source: **Physics Letters A - June 20, 2019 **Category: **Physics **Source Type: **research

**Chemical vapor deposition synthesis of Ge doped ZnO nanowires and the optical property investigation**

Publication date: Available online 19 June 2019Source: Physics Letters AAuthor(s): Ying LiangAbstractGe-doped ZnO nanowires with high quality were prepared with simple chemical vapor deposition method. The morphology, crystal structure and elemental distribution were characterized using SEM (scanning electron microscopy), HRTEM (high resolution transmission electron microscopy) and EDS (energy dispersive spectrometry) mapping approaches. The optical properties were investigated with combination of room-temperature CL (cathode ray luminescence) and variable temperature micro-PL methods. It is found for the first time that a...

**Source: **Physics Letters A - June 20, 2019 **Category: **Physics **Source Type: **research

**Comparison of information-theoretic products and inequalities for the lowest bound and unbound electronic states of H2+ based on exact calculation**

Publication date: Available online 17 June 2019Source: Physics Letters AAuthor(s): Sergey A. AstashkevichAbstractA study of information-theoretic properties of molecular bond on the example of the ground (bound) 1sσg and the lowest excited (unbound) 2pσu states of H2+ was conducted. Data about general information-theoretic measures, information products (Cramér-Rao, Fisher-Shannon information, and LMC complexity) and their inequalities in position and momentum spaces as a function of internuclear distance R=0.2–20 a.u. were obtained by an exact numerical calculation of the wave function. A systemat...

**Source: **Physics Letters A - June 18, 2019 **Category: **Physics **Source Type: **research

**Electrically controllable spin transport in bilayer graphene with Rashba spin-orbit interaction**

Publication date: Available online 14 June 2019Source: Physics Letters AAuthor(s): Qingtian Zhang, Junsong Jiang, Kwok Sum ChanAbstractWe study the spin transport in bilayer graphene nanoribbons (BGNs) in the presence of Rashba spin-orbit interaction (SOI) and external gate voltages. It is found that the spin polarization can be significantly enhanced by the interlayer asymmetry or longitudinal mirror asymmetry produced by external gate voltages. Rashba SOI alone in BGNs can only generate current with spin polarization along the in-plane y direction, but the polarization components can be found along the x, y and z directi...

**Source: **Physics Letters A - June 15, 2019 **Category: **Physics **Source Type: **research

**A no-go result for the quantum damped harmonic oscillator**

Publication date: Available online 14 June 2019Source: Physics Letters AAuthor(s): F. Bagarello, F. Gargano, F. RoccatiAbstractIn this letter we show that it is not possible to set up a canonical quantization for the damped harmonic oscillator using the Bateman lagrangian. In particular, we prove that no square integrable vacuum exists for the natural ladder operators of the system, and that the only vacua can be found as distributions. This implies that the procedure proposed by some authors is only formally correct, and requires a much deeper analysis to be made rigorous. (Source: Physics Letters A)

**Source: **Physics Letters A - June 15, 2019 **Category: **Physics **Source Type: **research

**Interpreting weak value amplification with a toy realist model**

Publication date: Available online 14 June 2019Source: Physics Letters AAuthor(s): Josiah Sinclair, David Spierings, Aharon Brodutch, Aephraim M. SteinbergAbstractConstructing an ontology for quantum theory is challenging, in part due to measurement back-action. The Aharonov-Albert-Vaidman weak measurement formalism provides a method to predict measurement results (weak values) when back-action is negligible. The weak value appears analogous to a classical conditional mean, yet can be complex and unbounded. We study weak values in the context of a recent quantum optical experiment involving two-photon interactions. The res...

**Source: **Physics Letters A - June 15, 2019 **Category: **Physics **Source Type: **research

**Controlling the stability and the electronic structure of transition metal dichalcogenide single layer under chemical doping**

Publication date: Available online 14 June 2019Source: Physics Letters AAuthor(s): M. Debbichi, L. Debbichi, S. LebègueAbstractBy means of ab initio calculation based on density-functional theory (DFT), we have investigated the electronic and optical properties of single layer MoSe2 under chemical doping by various groups, such as -H, -OH, -NH2 and -CH3. This work is generalized for all polymorph 1H, 1T, 1T′ and the new investigated phase 1T″. We found that all those functional groups (FG) bonded covalently to the chalcogen atom (Se). The evaluation of adsorption energy shows that the hydrogen atom binds...

**Source: **Physics Letters A - June 15, 2019 **Category: **Physics **Source Type: **research

**Efficient band structure engineering and visible-light response in ZrS2/GaS heterobilayer by electrical field or external strains**

Publication date: Available online 14 June 2019Source: Physics Letters AAuthor(s): Yanxing Zhang, Zongxian YangAbstractVia first-principle methods, the electronic structures and optical properties of 2D ZrS2/GaS van der Waals heterostructure (vdWH) are studied. It is found that the band alignment changes from type-II to type-I under negative electrical field, and compressive strains. The transition points are -0.2 V/Å and -1%, respectively. The band gap changes efficiently under positive electrical field and compressive strains. The tensile strains increase the optical adsorption coefficients in ultraviolet regions, ...

**Source: **Physics Letters A - June 15, 2019 **Category: **Physics **Source Type: **research

**Study on the dynamic critical behavior of a ferroelectric heterostructure**

Publication date: Available online 14 June 2019Source: Physics Letters AAuthor(s): Lian Cui, Chuanwen Chen, Yang XiangAbstractA Landau-Devonshire theory added in Landau–Khalatnikov dynamic equation has been used firstly to explore the dynamic critical behavior of a ferroelectric heterostructure composed of two different ferroelectric films. Two identical surface transition layers within each film are assumed, and an antiferroelectric interfacial coupling between two materials is considered. One interfacial parameter β is introduced to describe the differences of physical characteristics between two constituent f...

**Source: **Physics Letters A - June 15, 2019 **Category: **Physics **Source Type: **research

**Band structure and cluster model calculations of LaNiO3 compared to photoemission, O 1s X-ray absorption, and optical absorption spectra**

We present results for the density of states (DOS), the spectral weight, and the dielectric function ε2. The calculations are compared to previous photoemission (PES), O 1s X-ray absorption (XAS), as well as optical absorption spectra. Both band structure and cluster model results are in good agreement with the experimental data. We point out that this concordance is very rare and far from trivial; we argue that this may be due to the unusual characteristics of the ground state of LaNiO3.Graphical abstract (Source: Physics Letters A)

**Source: **Physics Letters A - June 15, 2019 **Category: **Physics **Source Type: **research

**Persistent currents and induced magnetization in presence of external magnetic field and transition probabilities in presence of combined laser pulse and external magnetic field for a confined hydrogen atom**

Publication date: Available online 12 June 2019Source: Physics Letters AAuthor(s): Vinod Prasad, Shalini Lumb Talwar, Sonia Lumb, G. Lefkidis, W. HübnerAbstractIn this work we propose to study an atom confined in a potential which consists of a Hulthén potential plus a ring-shaped potential. The atom is further subjected to a spherical confinement. The time-independent Schrödinger equation (TISE) of the system is solved numerically. Exact energy levels are obtained. The persistent current and induced magnetic field of such a confined atom is evaluated. Finally, the atomic system in this potential and confi...

**Source: **Physics Letters A - June 13, 2019 **Category: **Physics **Source Type: **research

**The deviation factor and divergences in quantum electrodynamics, concrete examples**

Publication date: Available online 12 June 2019Source: Physics Letters AAuthor(s): Lev SakhnovichAbstractWe consider the divergences in quantum electrodynamics. Our approach is based on ideas from the theory of generalized wave operators. In particular, we use the concept of the deviation factor. The deviation factor characterizes the deviations of the initial and final waves from the free waves. The approach is demonstrated on important examples. (Source: Physics Letters A)

**Source: **Physics Letters A - June 13, 2019 **Category: **Physics **Source Type: **research