作者机构:
[Dai, Zhi-Ping; Wang, Yi-Cheng] College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang 421002, China;[Liu, Xian-Jun] School of Mathematics Science, Hebei Normal University, Shijiazhuang 050024, China;College of Physics, Hebei Key Laboratory of Photophysics Research and Application, Hebei Normal University, Shijiazhuang 050024, China;Hebei Province Semiconductor Photoelectric Application Technology Innovation Center, Shijiazhuang 050000, China;[Dong, Jing-Kun; Shen, Shuang; Yang, Zhen-Jun] College of Physics, Hebei Key Laboratory of Photophysics Research and Application, Hebei Normal University, Shijiazhuang 050024, China<&wdkj&>Hebei Province Semiconductor Photoelectric Application Technology Innovation Center, Shijiazhuang 050000, China
通讯机构:
School of Mathematical Science, Hebei Normal University, Shijiazhuang, China
关键词:
Beam propagation;Cosine-gauss beams;Nonlocal optical media
通讯机构:
[Shiqing Tang] C;College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang 421002, China
关键词:
Berry phase;Dicke quantum phase transition;two impurity qubits;dispersive interaction;X-type state
摘要:
Abstract: In this paper, we investigate the effect of the Dicke quantum phase transition on the Berry phase of the two impurity qubits. The two impurity qubits only have dispersive interactions with the optical field of the Dicke quantum system. Therefore, the two impurity qubits do not affect the ground state energy of the Dicke Hamiltonian. We find that the Berry phase of the two impurity qubits has a sudden change at the Dicke quantum phase transition point. Therefore, the Berry phase of the two impurity qubits can be used as a phase transition signal for the Dicke quantum phase transition. In addition, the two impurity qubits change differently near the phase transition point at different times. We explain the reason for the different variations by studying the variation of the Berry phase of the two impurity qubits with the phase transition parameters and time. Finally, we investigated the variation of the Berry phases of the two impurity qubits with their initial conditions, and we found that their Berry phases also have abrupt changes with the initial conditions. Since the Dicke quantum phase transition is already experimentally executable, the research in this paper helps to provide a means for manipulating the Berry phase of the two impurity qubits. Keywords: Berry phase; Dicke quantum phase transition; two impurity qubits; dispersive interaction; X-type state
作者机构:
[Zhang, Li -Ting; Lan, Yu; Li, Lei] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Jin, Yao] Macao Polytech Univ, Macau 999078, Peoples R China.;[Xia, Li-Xin] Kashi Univ, Coll Phys & Elect Engn, Kashi 844006, Peoples R China.;[Huang, Wei-Qing; Huang, Gui-Fang] Hunan Univ, Sch Phys & Elect, Dept Appl Phys, Changsha 410082, Peoples R China.;[Hu, Wangyu] Hunan Univ, Sch Mat Sci & Engn, Changsha 410082, Peoples R China.
通讯机构:
[Yu Lan] C;[Wei-Qing Huang] D;College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang 421002, China<&wdkj&>Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China
作者机构:
[Jiang, Xi; Tang, Shiqing] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Tang, Shiqing] Hunan Normal Univ, Key Lab Low Dimens Quantum Struct & Quantum Contr, Minist Educ, Changsha 410081, Peoples R China.;[Li, Songsong] Nanchang Normal Univ, Coll Phys & Elect Informat, Nanchang 330032, Jiangxi, Peoples R China.
通讯机构:
[Shiqing Tang] C;College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang 421002, China<&wdkj&>Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha 410081, China
摘要:
Abstract: Hybrid quantum systems have attracted much attention due to the fact that they combine the advantages of different physical subsystems. Cavity QED (cavity quantum electrodynamics) with magnons is a hybrid quantum systems that combines a YIG (Yttrium Iron Garnet) sphere and a 3D (three-dimensional) rectangular microwave cavity. Based on this hybrid photon-magnon system, we obtain an approximate analytic solution by the RWA (rotating wave approximation) with an ingenious transformation. After skillfully diagonalizing the Hamiltonian, we show that the Kerr-nonlinearity interactions could yield a negativity value of the Wigner function, periodic quadrature squeezing effects, antibunching property, and field nonclassicality in the magnon. Our work may stimulate the study of nonclassicality of photon-magnon coupling systems and its potential applications in quantum information processing. Keywords: microwave cavity; photon; magnon; nonclassicality
通讯机构:
[Wei, XL ] H;[Yang, LW] X;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;Xiangtan Univ, Sch Phys & Optoelect, Xiangtan 411105, Hunan, Peoples R China.
摘要:
Tin-based selenides have been widely researched as electrode composites for lithium/sodium storage, ascribed to their relatively large theoretical specific capacity. However, the unsatisfactory electronic conductivity and the collapse of the structure associated with the large volume expansion lead to poor electrochemical performance and hinder their commercial application. Therefore, carbon-encapsulating MnSe/SnSe nanoboxes were designed and successfully prepared by an effortless wet-chemical method and selenization treatment for lithium-ion batteries (LIBs) and sodium-ion batteries (NIBs). The MnSe/SnSe@C-M (MSS) nanoboxes exhibited a reversible capacity of 965 mA h g(-1) after 240 cycles at 0.2 A g(-1) and superior cyclability of 557 mA h g(-1) after 900 cycles at 0.5 A g(-1) for LIBs. For NIBs, the MnSe/SnSe@C-M nanoboxes also displayed a high capacity of 500 mA h g(-1) after 78 cycles at 0.5 A g(-1) and good cyclability of 497.2 mA h g(-1) after 262 cycles at 2 A g(-1). The improved electrochemical performance could be associated with the following reasons: carbon layer can hinder volume change, avoid active material falling off from the copper foil, and further enhance the stability during cycling process. The existence of MnSe/SnSe heterostructures can efficaciously restrain the agglomeration of the element Sn-0 and improve the reversibility of alloying reaction. The strong electronic coupling of Sn-C and Se-C chemical bonds between the carbon shell and SnSe promote fast electron/ion transport during the cycling process. Motivated by the excellent electrochemical properties of LIBs and NIBs, commercial LiFePO4 (LFP)/Na3V2(PO4)(3) (NVP) were paired with MnSe/SnSe@C-M to assemble and test its full-cell performance.
通讯机构:
[Yipeng Zhao] C;[Gang Ouyang] K;College of Physics and Electronic Engineering, Hengyang Normal University , Hengyang 421008, China<&wdkj&>Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Key Laboratory for Matter Microstructure and Function of Hunan Province, School of Physics and Electronics, Hunan Normal University , Changsha 410081, China
摘要:
One-dimensional single-wall carbon nanotube (1D-SWCNT)@MoS2 van der Waals (vdW) heteronanotubes (HNTs) have inherited extensive attention due to their fascinating properties and increasing mature methods. However, the curvature and chirality dependence of photovoltaic properties in such kind of 1D systems remain unclear. In our work, we explore the electronic and photoelectric properties of 1D-SWCNT@MoS2 vdW HNTs based on the atomic-bond-relaxation approach and the modified detailed balance principle by quantization of band offset and carrier transport behaviors. We find that the optimized power conversion efficiency (PCE) of zigzag-SWCNT@zigzag-MoS2 HNTs is ∼5.3% at the diameter of 3.1 nm, while that of zigzag-SWCNT@armchair-MoS2 HNTs is ∼4.9% at 3.3 nm. Moreover, the PCE can be enhanced further by intercalating h-BN layers at the interface of 1D-vdW HNTs. Our results suggest that 1D-SWCNT@MoS2 HNTs can be served as promising building blocks for the new type of photovoltaic devices.
期刊:
Environmental Science and Pollution Research,2022年30(12):35223-35237 ISSN:0944-1344
通讯作者:
Jiang, Fuliang
作者机构:
[Tan, Biao; Zhang, Mian; Zhang, Chao; Hao, Yuying; Yang, Xiaotong; Jiang, Fuliang; Li, Haoyu] Univ South China, Sch Resource Sr Environm & Safety Engn, Hengyang 421001, Peoples R China.;[He, Huiting; Li, Shiyan; Jiang, Fuliang] Hunan Inst Technol, Sch Safety & Management Engn, Hengyang 421002, Peoples R China.;[Hu, Tao; Mo, Yixiang; Jiang, Fuliang] Hengyang Normal Univ, Sch Phys & Elect Engn, Hengyang 421001, Peoples R China.;[Hu, Tao; Mo, Yixiang; Jiang, Fuliang] Hunan Prov Engn Res Ctr Uranium Mineral Explorat, Hengyang 421001, Peoples R China.
通讯机构:
[Jiang, Fuliang] S;School of Resource & Environment and Safety Engineering, University of South China, Hengyang, 421001, China.;School of Safety and Management Engineering, Hunan Institute of Technology, Hengyang, 421002, China.;School of Physics and Electronic Engineering, Hengyang Normal University, Hengyang, 421001, China.;Hunan Provincial Engineering Research Center for Uranium Mineral Exploration Technology, Hengyang, 421001, China.
关键词:
High temperature action;Uranium-bearing granite;Thermal damage;Physical and mechanical properties;Radon exhalation
作者机构:
[Luo, Fei; Li, Yue] Univ South China, Coll Comp Sci, Hengyang 421001, Peoples R China.;[Zhu, Yapei] Hengyang Normal Univ, Fac Phys & Elect Informat Sci, Hengyang 421002, Peoples R China.
通讯机构:
[Yapei Zhu] F;Faculty of Physics and Electronic Information Science, Hengyang Normal University, Hengyang 421002, China
关键词:
versatile video coding;QTMT;CU partition;temporal prediction model
摘要:
Abstract: Versatile video coding (VVC) adopts an advanced quad-tree plus multi-type tree (QTMT) coding structure to obtain higher compression efficiency, but it comes at the cost of a considerable increase in coding complexity. To effectively reduce the coding complexity of the QTMT-based coding unit (CU) partition, we propose a fast inter CU partition method based on a temporal prediction model, which includes early termination QTMT partition and early skipping multi-type tree (MT) partition. Firstly, according to the position of the current CU, we extract the optimal CU partition information of the position corresponding to the previously coded frames. We then establish a temporal prediction model based on temporal CU partition information to predict the current CU partition. Finally, to reduce the cumulative of errors of the temporal prediction model, we further extract the motion vector difference (MVD) of the CU to determine whether the QTMT partition can be terminated early. The experimental results show that the proposed method can reduce the inter coding complexity of VVC by 23.19% on average, while the Bjontegaard delta bit rate (BDBR) is only increased by 0.97% on average under the Random Access (RA) configuration. Keywords: versatile video coding; QTMT; CU partition; temporal prediction model
作者机构:
[Jiang, Xi; Zhang, Ziqiu; Tang, Shiqing] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Tang, Shiqing] Hunan Normal Univ, Key Lab Low Dimens Quantum Struct & Quantum Contr, Minist Educ, Changsha 410081, Peoples R China.
通讯机构:
[Shiqing Tang] C;College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang 421002, China<&wdkj&>Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha 410081, China
摘要:
Abstract: The cross fusion of quantum mechanics and information science forms quantum information science. Quantum logic gates and quantum entanglement are very important building blocks in quantum information processing. In this paper, we propose one-step schemes for realizing quantum swap gates and generating two-mode entangled coherent states via circuit QED. In our scheme, due to the adiabatic elimination of the excited state of the qutrit under the condition of large detuning, the decoherence of the spontaneous emission of the qutrit can be ignored. The fidelity of the quantum swap gate remains at a very high level. In addition, we also explore the nonclassical properties of two-mode entangled coherent states prepared in our scheme by addressing the second-order correlation function and intermodal squeezing. In particular, two classes of entangled coherent states demonstrate distinct entanglement and nonclassical behavior. Keywords: circuit QED; microwave; optical; swap gates; qubit
摘要:
A uranium tailing pond in southern China is the largest in Asia. For historical reasons, uranium tailings stored in the pond have been in an acidic environment for a long time, which has caused great difficulties for decommissioning treatment of the pond. In this study, uranium tailings were taken from the beach surface of the pond as the research object. Then, 11 kinds of solidified samples of uranium tailings with different compositional ratios were prepared using water glass and sodium hydroxide, as alkali activators, and mixed with metakaolin, fly ash, and PVA or basalt fibers. The resulting solidified samples were examined in terms of microscopic characterization, compressive strength, tensile strength, resistivity, and U(VI) leaching. The results showed that, with increased fiber content, the compressive strength of samples first increased and then decreased, while the tensile strength increased continuously. The body volume resistivities first increased and then decreased and, with increased time, the leaching rate decreased continuously and finally tended to stabilize. The compressive strength and volume resistivity of samples were negatively correlated with the U(VI) leaching rate and cumulative leaching fraction. Considering the physical mechanics and U(VI) leaching resistance properties of these bodies, the best fiber proportion was concluded to be the addition of 0.2-wt% PVA fiber and 0.6-wt% basalt fiber.
摘要:
The study of the spin-orbit coupling (SOC) effect is an active research field in physics and it is of great interest for materials with large Rashba spin splitting (RSS) in spintronics applications. In this report, based on firstprinciples calculations, we propose the heterostructure of MoS2/Bi2Te3 with giant RSS duo to the lack of spatial inversion symmetry and the intrinsic electric field perpendicular to the heterostructure. Furthermore, it is found that the electronic and RSS can be tuned effectively by layers of MoS2 and Bi2Te3. When the Bi2Te3 thickness is less than 2QL, these MoS2/Bi2Te3 heterojunction systems exhibit semiconductor properties. The magnitude of the RSS in these MoS2/Bi2Te3 heterojunctions changes with the thickness, and the largest band splitting is found in the (MoS2)(1) (Bi2Te3)(2) heterostructure with a Rashba coefficient of similar to 2.5 eV angstrom, which is a very large value among two-dimensional (2D) materials. While the interlayer distance and charge transfer remain stable at about 3.5 angstrom and 0.1 e, respectively. Through layer-projected band structure analysis, it is proven that the electronic states of these quantum well states (QWSs) are mainly contributed by Bi2Te3, while the MoS2 layer only plays an inductive role and does not contribute to the QWSs electrons. In addition, strain only plays a minor role in the Rashba effect in the MoS2/Bi2Te3 heterojunction, which is mainly caused by the breaking of the spatial inversion symmetry. The giant and tunable Rashba-type SOC of the MoS2/Bi2Te3 heterostructure suggests that it is a type of promising materials for spintronic applications.
摘要:
Achieving highly directive radiation with broadband operation, low scattering, and thin profile for a circularly polarized (CP) antenna is particularly challenging and yet rarely reported. Here, we propose a strategy of a CP Cassegrain meta-antenna by combining a planar helical antenna, a metasurface main reflector, and a metamaterial subreflector. The main reflector is designed to achieve focusing for CP waves at 13 GHz. The subreflector is chessboard-configured chiral metamaterial slab composed of two different types of chiral meta-atoms, aiming to achieve spin- and direction-selective CP transmissions and reflections. The distance between two reflectors is half of focal length, which enables our antenna to be dubbed as a folded reflectarray. The low radar cross section (RCS) is achieved based on scattering cancellation technique by realizing near 180 degrees reflection phase difference between two neighboring chessboard submeta-atoms. Thanks to the architecture of the two reflectors, the proposed antenna exhibits high gain and low profile simultaneously according to image theory. For verification, a planar CP Cassegrain antenna, excited by a left-handed CP (LCP) planar helical antenna, is numerically studied, fabricated, and experimentally measured. Numerical results are in good agreement with the experimental ones, showing a peak right-handed CP (RCP) gain of 26.6 dBi at 12.6 GHz. Furthermore, the backward monostatic RCS of the antenna is dramatically reduced over -10 dB in a broad bandwidth from 8.4 to 15.7 GHz when it is illuminated by an LCP planar wave. Our proposed Cassegrain antenna features simultaneously broadband, high gain, low profile, and low RCS, providing a new avenue to low-profile CP reflectarrays with invisibility.
作者机构:
[Tang, Shiqing] Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421002, Peoples R China.;[Li, Dongxiao; Yang, Chong] Shenyang Normal Univ, Coll Phys Sci & Technol, Shenyang 110034, Peoples R China.;[Shao, Xiaoqiang] Northeast Normal Univ, Ctr Quantum Sci & Sch Phys, Changchun 130024, Peoples R China.;[Shao, Xiaoqiang] Northeast Normal Univ, Ctr Adv Optoelect Funct Mat Res, Minist Educ, Changchun 130024, Peoples R China.;[Shao, Xiaoqiang] Northeast Normal Univ, Minist Educ, Key Lab UV Light Emitting Mat & Technol, Changchun 130024, Peoples R China.
通讯机构:
[Dongxiao Li; Xiaoqiang Shao] C;College of Physics Science and Technology, Shenyang Normal University, Shenyang 110034, China<&wdkj&>Center for Quantum Sciences and School of Physics, Northeast Normal University, Changchun 130024, China<&wdkj&>Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, Changchun 130024, China
摘要:
Abstract: Multiqubit CCZ gates form one of the building blocks of quantum algorithms and have been involved in achieving many theoretical and experimental triumphs. Designing a simple and efficient multiqubit gate for quantum algorithms is still by no means trivial as the number of qubits increases. Here, by virtue of the Rydberg blockade effect, we propose a scheme to rapidly implement a three-Rydberg-atom CCZ gate via a single Rydberg pulse, and successfully apply the gate to realize the three-qubit refined Deutsch–Jozsa algorithm and three-qubit Grover search. The logical states of the three-qubit gate are encoded to the same ground states to avoid an adverse effect of the atomic spontaneous emission. Furthermore, there is no requirement for individual addressing of atoms in our protocol. Keywords: multiqubit controlled gate; Rydberg blockade; quantum algorithm