Highlights

    Please wait a minute...
    For selected: Toggle thumbnails
    Quantization of the band at the surface of charge density wave material 2H-TaSe2
    Man Li(李满), Nan Xu(徐楠), Jianfeng Zhang(张建丰), Rui Lou(娄睿), Ming Shi(史明), Lijun Li(黎丽君), Hechang Lei(雷和畅), Cedomir Petrovic, Zhonghao Liu(刘中灏), Kai Liu(刘凯), Yaobo Huang(黄耀波), and Shancai Wang(王善才)
    Chin. Phys. B, 2021, 30 (4): 047305.   DOI: 10.1088/1674-1056/abe9a8
    Abstract83)      PDF (1794KB)(242)      
    By using angle-resolved photoemission spectroscopy (ARPES) combined with the first-principles electronic structure calculations, we report the quantized states at the surface of a single crystal 2H-TaSe2. We have observed sub-bands of quantized states at the three-dimensional Brillouin zone center due to a highly dispersive band with light effective mass along kz direction. The quantized sub-bands shift upward towards EF while the bulk band at $\varGamma$ shifts downward with the decrease of temperature across charge density wave (CDW) formation. The band shifts could be intimately related to the CDW. While neither the two-dimensional Fermi-surface nesting nor purely strong electron-phonon coupling can explain the mechanism of CDW in 2H-TaSe2, our experiment may ignite the interest in understanding the CDW mechanism in this family.
    Nodal superconducting gap in LiFeP revealed by NMR: Contrast with LiFeAs
    A F Fang(房爱芳), R Zhou(周睿), H Tukada, J Yang(杨杰), Z Deng(邓正), X C Wang(望贤成) , C Q Jin(靳常青), and Guo-Qing Zheng(郑国庆)
    Chin. Phys. B, 2021, 30 (4): 047403.   DOI: 10.1088/1674-1056/abec37
    Abstract27)      PDF (1513KB)(151)      
    Identifying the uniqueness of FeP-based superconductors may shed new lights on the mechanism of superconductivity in iron-pnictides. Here, we report nuclear magnetic resonance (NMR) studies on LiFeP and LiFeAs which have the same crystal structure but different pnictogen atoms. The NMR spectrum is sensitive to inhomogeneous magnetic fields in the vortex state and can provide the information on the superconducting pairing symmetry through the temperature dependence of London penetration depth ΛL. We find that Λ L saturates below T ∼ 0.2 T c in LiFeAs, where T c is the superconducting transition temperature, indicating nodeless superconducting gaps. Furthermore, by using a two-gaps model, we simulate the temperature dependence of ΛL and obtain the superconducting gaps of LiFeAs, as $\varDelta_1 = 1.2$ kB Tc and $\varDelta_2 = 2.8$ kB T c, in agreement with previous result from spin-lattice relaxation. For LiFeP, in contrast, Λ L does not show any saturation down to T ∼ 0.03 T c, indicating nodes in the superconducting gap function. Finally, we demonstrate that strong spin fluctuations with diffusive characteristics exist in LiFeP, as in some cuprate high temperature superconductors.
    Two-dimensional MnN utilized as high-capacity anode for Li-ion batteries
    Junping Hu(胡军平), Zhangyin Wang(王章寅), Genrui Zhang(张根瑞), Yu Liu(刘宇), Ning Liu(刘宁), Wei Li(李未), Jianwen Li(李健文), Chuying Ouyang(欧阳楚英), and Shengyuan A. Yang(杨声远)
    Chin. Phys. B, 2021, 30 (4): 046302.   DOI: 10.1088/1674-1056/abdda8
    Abstract38)      PDF (1351KB)(18)      
    When developing high performance lithium-ion batteries, high capacity is one of the key indicators. In the last decade, the progress of two-dimensional (2D) materials has provided new opportunities for boosting the storage capacity. Here, based on first-principles calculation method, we predict that MnN monolayer, a recently proposed 2D nodal-loop half-metal containing the metallic element Mn, can be used as a super high-capacity lithium-ion batteries anode. Its theoretical capacity is above 1554 mAh/g, more than four times that of graphite. Meanwhile, it also satisfies other requirements for a good anode material. Specifically, we demonstrate that MnN is mechanically, dynamically, and thermodynamically stable. The configurations before and after lithium adsorption exhibit good electrical conductivity. The study of Li diffusion on its surface reveals a very low diffusion barrier (∼ 0.12 eV), indicating excellent rate performance. The calculated average open-circuit voltage of the corresponding half-cell at full charge is also very low (∼ 0.22 V), which facilitates higher operating voltage. In addition, the lattice changes of the material during lithium intercalation are very small (∼ 1.2%-∼ 4.8%), which implies good cycling performance. These results suggest that 2D MnN can be a very promising anode material for lithium-ion batteries.
    Generation of wideband tunable femtosecond laser based on nonlinear propagation of power-scaled mode-locked femtosecond laser pulses in photonic crystal fiber
    Zhiguo Lv(吕志国) and Hao Teng(滕浩)
    Chin. Phys. B, 2021, 30 (4): 044209.   DOI: 10.1088/1674-1056/abe231
    Abstract51)      PDF (1089KB)(46)      
    We implement an experimental study for the generation of wideband tunable femtosecond laser with a home-made power-scaled mode-locked fiber oscillator as the pump source. By coupling the sub-100 fs mode-locked pulses into a nonlinear photonic crystal fiber (NL-PCF), the exited spectra have significant nonlinear broadening and cover a spectra range of hundreds of nm. In experiment, by reasonably optimizing the structure parameters of NL-PCF and regulating the power of the incident pulses, femtosecond laser with tuning range of 900-1290 nm is realized. The research approach promotes the development of femtosecond lasers with center wavelengths out of the traditional laser gain media toward the direction of simplicity and ease of implementation.
    X-ray absorption investigation of the site occupancies of the copper element in nominal Cu3Zn(OH)6FBr
    Ruitang Wang(王瑞塘), Xiaoting Li(李效亭), Xin Han(韩鑫), Jiaqi Lin(林佳琪), Yong Wang(王勇), Tian Qian(钱天), Hong Ding(丁洪), Youguo Shi(石友国), and Xuerong Liu(柳学榕)
    Chin. Phys. B, 2021, 30 (4): 046102.   DOI: 10.1088/1674-1056/abe0c8
    Abstract37)      PDF (913KB)(12)      
    With Zn substitution to the three-dimensional antiferromagnetically ordered barlowite Cu4(OH)6FBr, Cu3Zn(OH)6FBr shows no magnetic phase transition down to 50 mK, and the system is suggested to be a two-dimensional kagomé quantum spin liquid [Chin. Phys. Lett. 34 077502 (2017)]. A key issue to identify such phase diagram is the exact chemical formula of the substituted compound. With Cu L-edge x-ray absorption spectrum (XAS) combined with the MultiX XAS calculations, we evaluate the Cu concentration in a nominal Cu3Zn(OH)6FBr sample. Our results show that although the Cu concentration is 2.80, close to the expected value, there is 34% residual Cu occupation in intersite layers between kagomé layers. Thus the Zn substitution of the intersite layers is not complete, and likely it intrudes the kagomé layers.
    Quantum nature of proton transferring across one-dimensional potential fields
    Cheng Bi(毕成), Quan Chen (陈泉), Wei Li(李伟), and Yong Yang(杨勇)
    Chin. Phys. B, 2021, 30 (4): 046601.   DOI: 10.1088/1674-1056/abe114
    Abstract27)      PDF (1514KB)(18)      
    Proton transfer plays a key role in the applications of advanced energy materials as well as in the functionalities of biological systems. In this work, based on the transfer matrix method, we study the quantum effects of proton transfer in a series of one-dimensional (1D) model potentials and numerically calculate the quantum probability of transferring across single and double barriers (wells). In the case of single barriers, when the incident energies of protons are above the barrier height, the quantum oscillations in the transmission coefficients depend on the geometric shape of the barriers. It is found that atomic resonant tunneling (ART) not only presents in the rectangular single well and rectangular double barriers as expected, but also exists in the other types of potential wells and double barriers. For hetero-structured double barriers, there is no resonant tunneling in the classical forbidden zone, i.e., in the case when the incident energy (E i) is lower than the barrier height (E b). Furthermore, we have provided generalized analysis on the characteristics of transmission coefficients of hetero-structured rectangular double barriers.
    Transport property of inhomogeneous strained graphene
    Bing-Lan Wu(吴冰兰), Qiang Wei(魏强), Zhi-Qiang Zhang(张智强), and Hua Jiang(江华)
    Chin. Phys. B, 2021, 30 (3): 030504.   DOI: 10.1088/1674-1056/abe3e3
    Abstract386)   HTML7)    PDF (1974KB)(444)      
    In analogy to real magnetic field, the pseudo-magnetic field (PMF) induced by inhomogeneous strain can also form the Landau levels and edge states. In this paper, the transport properties of graphene under inhomogeneous strain are studied. We find that the Landau levels have non-zero group velocity, and construct one-dimensional conducting channels. In addition, the edge states and the Landau level states in PMF are both fragile under disorder. We also confirm that the backscattering of these states could be suppressed by applying a real magnetic filed (MF). Therefore, the transmission coefficient for each conducting channel can be manipulated by adjusting the MF strength, which indicates the application of switching devices.
    Enhanced spin-orbit torque efficiency in Pt100-xNix alloy based magnetic bilayer
    Congli He(何聪丽), Qingqiang Chen(陈庆强), Shipeng Shen(申世鹏), Jinwu Wei(魏晋武), Hongjun Xu(许洪军), Yunchi Zhao(赵云驰), Guoqiang Yu(于国强), and Shouguo Wang(王守国)
    Chin. Phys. B, 2021, 30 (3): 037503.   DOI: 10.1088/1674-1056/abe3f4
    Abstract175)   HTML4)    PDF (932KB)(222)      
    The binary alloy/ferromagnetic metal heterostructure has drawn extensive attention in the research field of spin-orbit torque (SOT) due to the potential enhancement of SOT efficiency via composition engineering. In this work, the magnetic properties and SOT efficiency in the Pt100-xNix/Ni78Fe22 bilayers were investigated via the spin-torque ferromagnetic resonance (ST-FMR) technique. The effective magnetic anisotropy field and effective damping constant extracted by analyzing the ST-FMR spectra show a weak dependence on the Ni concentration. The effective spin-mixing conductance of $8.40\times 10^14 \Omega ^-1\cdot\rm m^-2$ and the interfacial spin transparency T in of 0.59 were obtained for the sample of Pt70Ni30/NiFe bilayer. More interestingly, the SOT efficiency that is carefully extracted from the angular dependence of ST-FMR spectra shows a nonmonotonic dependence on the Ni concentration, which reaches the maximum at x = 18. The enhancement of the SOT efficiency by alloying the Ni with Pt shows potential in lowering the critical switching current. Moreover, alloying relatively cheaper Ni with Pt may promote to reduce the cost of SOT devices.
    Plasmonic properties of graphene on uniaxially anisotropic substrates
    Shengchuan Wang(汪圣川), Bin You(游斌), Rui Zhang(张锐), Kui Han(韩奎), Xiaopeng Shen(沈晓鹏, and Weihua Wang(王伟华)
    Chin. Phys. B, 2021, 30 (3): 037801.   DOI: 10.1088/1674-1056/abd168
    Abstract124)   HTML2)    PDF (17038KB)(303)      
    Most of the current graphene plasmonic researches are based on the substrates with isotropic dielectric constant such as silicon. In this work, we investigate optical properties of graphene nanoribbon arrays placed on a uniaxially anisotropic substrate, where the anisotropy provides an additional freedom to tune the behaviors of graphene plasmons, and its effect can be described by a simple effective formula. In practice, the substrates of semi-infinite and finite thickness are discussed by using both the formula and full wave simulations. Particularly, the dielectric constants $\varepsilon_ \parallel $ and $\varepsilon_ \bot $ approaching zero are intensively studied, which show different impacts on the transverse magnetic (TM) surface modes. In reality, the hexagonal boron nitride (hBN) can be chosen as the anisotropic substrate, which is also a hyperbolic material in nature.
    Delta-Davidson method for interior eigenproblem in many-spin systems
    Haoyu Guan(关浩宇) and Wenxian Zhang(张文献)
    Chin. Phys. B, 2021, 30 (3): 030205.   DOI: 10.1088/1674-1056/abd74a
    Abstract95)   HTML2)    PDF (659KB)(109)      
    Many numerical methods, such as tensor network approaches including density matrix renormalization group calculations, have been developed to calculate the extreme/ground states of quantum many-body systems. However, little attention has been paid to the central states, which are exponentially close to each other in terms of system size. We propose a delta-Davidson (DELDAV) method to efficiently find such interior (including the central) states in many-spin systems. The DELDAV method utilizes a delta filter in Chebyshev polynomial expansion combined with subspace diagonalization to overcome the nearly degenerate problem. Numerical experiments on Ising spin chain and spin glass shards show the correctness, efficiency, and robustness of the proposed method in finding the interior states as well as the ground states. The sought interior states may be employed to identify many-body localization phase, quantum chaos, and extremely long-time dynamical structure.
    Evolution of domain structure in Fe3GeTe2
    Siqi Yin(尹思琪), Le Zhao(赵乐), Cheng Song(宋成), Yuan Huang(黄元), Youdi Gu(顾有地), Ruyi Chen(陈如意), Wenxuan Zhu(朱文轩), Yiming Sun(孙一鸣), Wanjun Jiang(江万军), Xiaozhong Zhang(章晓中), and Feng Pan(潘峰)
    Chin. Phys. B, 2021, 30 (2): 027505.   DOI: 10.1088/1674-1056/abd693
    Abstract404)   HTML2)    PDF (1057KB)(434)      
    Two-dimensional (2D) magnets provide an ideal platform to explore new physical phenomena in fundamental magnetism and to realize the miniaturization of magnetic devices. The study on its domain structure evolution with thickness is of great significance for better understanding the 2D magnetism. Here, we investigate the magnetization reversal and domain structure evolution in 2D ferromagnet Fe3GeTe2 (FGT) with a thickness range of 11.2-112 nm. Three types of domain structures and their corresponding hysteresis loops can be obtained. The magnetic domain varies from a circular domain via a dendritic domain to a labyrinthian domain with increasing FGT thickness, which is accompanied by a transition from squared to slanted hysteresis loops with reduced coercive fields. These features can be ascribed to the total energy changes from exchange interaction-dominated to dipolar interaction-dominated with increasing FGT thickness. Our finding not only enriches the fundamental magnetism, but also paves a way towards spintronics based on 2D magnet.
    Modulation of the second-harmonic generation in MoS2 by graphene covering
    Chunchun Wu(吴春春), Nianze Shang(尚念泽), Zixun Zhao(赵子荀), Zhihong Zhang(张智宏), Jing Liang(梁晶), Chang Liu(刘畅), Yonggang Zuo(左勇刚), Mingchao Ding(丁铭超), Jinhuan Wang(王金焕), Hao Hong(洪浩), Jie Xiong(熊杰), and Kaihui Liu(刘开辉)
    Chin. Phys. B, 2021, 30 (2): 027803.   DOI: 10.1088/1674-1056/abd77f
    Abstract234)   HTML3)    PDF (864KB)(327)      
    Nonlinear optical frequency mixing, which describes new frequencies generation by exciting nonlinear materials with intense light field, has drawn vast interests in the field of photonic devices, material characterization, and optical imaging. Investigating and manipulating the nonlinear optical response of target materials lead us to reveal hidden physics and develop applications in optical devices. Here, we report the realization of facile manipulation of nonlinear optical responses in the example system of MoS2 monolayer by van der Waals interfacial engineering. We found that, the interfacing of monolayer graphene will weaken the exciton oscillator strength in MoS2 monolayer and correspondingly suppress the second harmonic generation (SHG) intensity to 30% under band-gap resonance excitation. While with off-resonance excitation, the SHG intensity would enhance up to 130%, which is conjectured to be induced by the interlayer excitation between MoS2 and graphene. Our investigation provides an effective method for controlling nonlinear optical properties of two-dimensional materials and therefore facilitates their future applications in optoelectronic and photonic devices.
    Complex coordinate rotation method based on gradient optimization
    Zhi-Da Bai(白志达), Zhen-Xiang Zhong(钟振祥), Zong-Chao Yan(严宗朝), and Ting-Yun Shi(史庭云)
    Chin. Phys. B, 2021, 30 (2): 023101.   DOI: 10.1088/1674-1056/abc156
    Abstract133)   HTML0)    PDF (586KB)(154)      
    In atomic, molecular, and nuclear physics, the method of complex coordinate rotation is a widely used theoretical tool for studying resonant states. Here, we propose a novel implementation of this method based on the gradient optimization (CCR-GO). The main strength of the CCR-GO method is that it does not require manual adjustment of optimization parameters in the wave function; instead, a mathematically well-defined optimization path can be followed. Our method is proven to be very efficient in searching resonant positions and widths over a variety of few-body atomic systems, and can significantly improve the accuracy of the results. As a special case, the CCR-GO method is equally capable of dealing with bound-state problems with high accuracy, which is traditionally achieved through the usual extreme conditions of energy itself.
    Superconducting anisotropy and vortex pinning in CaKFe4As4 and KCa2Fe4As4F2
    A B Yu(于奥博), Z Huang(黄喆), C Zhang(张驰), Y F Wu(吴宇峰), T Wang(王腾), T Xie(谢涛), C Liu(刘畅), H Li(李浩), W Peng(彭炜), H Q Luo(罗会仟), G Mu(牟刚), H Xiao(肖宏), L X You(尤立星), and T Hu(胡涛)
    Chin. Phys. B, 2021, 30 (2): 027401.   DOI: 10.1088/1674-1056/abcf98
    Abstract138)   HTML0)    PDF (1531KB)(115)      
    The vortex pinning determining the current carrying capacity of a superconductor is an important property to the applications of superconducting materials. For layered superconductors, the vortex pinning can be enhanced by a strong interlayer interaction in accompany with a suppression of superconducting anisotropy, which remains to be investigated in iron based superconductors (FeSCs) with the layered structure. Here, based on the transport and magnetic torque measurements, we experimentally investigate the vortex pinning in two bilayer FeSCs, CaKFe4As4(Fe1144) and KCa2Fe4As4F2(Fe12442), and compare their superconducting anisotropy γ. While the anisotropy γ ≈ 3 for Fe1144 is much smaller than γ ≈ 15 in Fe12442 around T c, a higher flux pinning energy as evidenced by a higher critical current density is found in Fe1144, as compared with the case of Fe12442. In combination with the literature data of Ba0.72K0.28Fe2As2 and NdFeAsO0.82F0.18, we reveal an anti-correlation between the pinning energy and the superconducting anisotropy in these FeSCs. Our results thus suggest that the interlayer interaction can not be neglected when considering the vortex pinning in FeSCs.
    High-resolution bone microstructure imaging based on ultrasonic frequency-domain full-waveform inversion
    Yifang Li(李义方), Qinzhen Shi(石勤振), Ying Li(李颖), Xiaojun Song(宋小军), Chengcheng Liu(刘成成), Dean Ta(他得安), and Weiqi Wang(王威琪)
    Chin. Phys. B, 2021, 30 (1): 014302.   DOI: 10.1088/1674-1056/abc7aa
    Abstract341)   HTML0)    PDF (9210KB)(743)      
    The main challenge in bone ultrasound imaging is the large acoustic impedance contrast and sound velocity differences between the bone and surrounding soft tissue. It is difficult for conventional pulse-echo modalities to give accurate ultrasound images for irregular bone boundaries and microstructures using uniform sound velocity assumption rather than getting a prior knowledge of sound speed. To overcome these limitations, this paper proposed a frequency-domain full-waveform inversion (FDFWI) algorithm for bone quantitative imaging utilizing ultrasonic computed tomography (USCT). The forward model was calculated in the frequency domain by solving the full-wave equation. The inverse problem was solved iteratively from low to high discrete frequency components via minimizing a cost function between the modeled and measured data. A quasi-Newton method called the limited-memory Broyden-Fletcher-Goldfarb-Shanno algorithm (L-BFGS) was utilized in the optimization process. Then, bone images were obtained based on the estimation of the velocity and density. The performance of the proposed method was verified by numerical examples, from tubular bone phantom to single distal fibula model, and finally with a distal tibia-fibula pair model. Compared with the high-resolution peripheral quantitative computed tomography (HR-pQCT), the proposed FDFWI can also clearly and accurately presented the wavelength scaled pores and trabeculae in bone images. The results proved that the FDFWI is capable of reconstructing high-resolution ultrasound bone images with sub-millimeter resolution. The parametric bone images may have the potential for the diagnosis of bone disease.
    Doping effects of transition metals on the superconductivity of (Li,Fe)OHFeSe films
    Dong Li(李栋), Peipei Shen(沈沛沛), Sheng Ma(马晟), Zhongxu Wei(魏忠旭), Jie Yuan(袁洁), Kui Jin(金魁), Li Yu(俞理), Fang Zhou(周放), Xiaoli Dong(董晓莉), and Zhongxian Zhao(赵忠贤)
    Chin. Phys. B, 2021, 30 (1): 017402.   DOI: 10.1088/1674-1056/abd2ab
    Abstract200)   HTML0)    PDF (998KB)(286)      
    The doping effects of transition metals (TMs = Mn, Co, Ni, and Cu) on the superconducting critical parameters are investigated in the films of iron selenide (Li,Fe)OHFeSe. The samples are grown via a matrix-assisted hydrothermal epitaxy method. Among the TMs, the elements of Mn and Co adjacent to Fe are observed to be incorporated into the crystal lattice more easily. It is suggested that the doped TMs mainly occupy the iron sites of the intercalated (Li,Fe)OH layers rather than those of the superconducting FeSe layers. We find that the critical current density J c can be enhanced much more strongly by the Mn dopant than the other TMs, while the critical temperature T c is weakly affected by the TM doping.
    Electric gating of the multichannel conduction in LaAlO3/SrTiO3 superlattices
    Shao-Jin Qi(齐少锦), Xuan Sun(孙璇), Xi Yan(严曦), Hui Zhang(张慧), Hong-Rui Zhang(张洪瑞), Jin-E Zhang(张金娥), Hai-Lin Huang(黄海林), Fu-Rong Han(韩福荣), Jing-Hua Song(宋京华), Bao-Gen Shen(沈保根), and Yuan-Sha Chen(陈沅沙)
    Chin. Phys. B, 2021, 30 (1): 017301.   DOI: 10.1088/1674-1056/abc54c
    Abstract117)   HTML0)    PDF (874KB)(96)      
    The electric gating on the transport properties of two-dimensional electron gas (2DEG) at the interface of LaAlO3/SrTiO3 (LAO/STO) heterostructure has attracted great research interest due to its potential application in field-effect devices. Most of previous works of gate effect were focused on the LAO/STO heterostructure containing only one conductive interface. Here, we systematically investigated the gate effect on high-quality LAO/STO superlattices (SLs) fabricated on the TiO2-terminated (001) STO substrates. In addition to the good metallicity of all SLs, we found that there are two types of charge carriers, the majority carriers and the minority carriers, coexisting in the SLs. The sheet resistance of the SLs with a fixed thickness of the LAO layer increases monotonically as the thickness of the STO layer increases. This is derived from the dependence of the minority carrier density on the thickness of STO. Unlike the LAO/STO heterostructure in which minority and majority carriers are simultaneously modulated by the gate effect, the minority carriers in the SLs can be tuned more significantly by the electric gating while the density of majority carriers is almost invariable. Thus, we consider that the minority carriers may mainly exist in the first interface near the STO substrate that is more sensitive to the back-gate voltage, and the majority carriers exist in the post-deposited STO layers. The SL structure provides the space separation for the multichannel conduction in the 2DEG, which opens an avenue for the design of field-effect devices based on LAO/STO heterostructure.
    High temperature strain glass in Ti-Au and Ti-Pt based shape memory alloys
    Shuai Ren(任帅), Chang Liu(刘畅), and Wei-Hua Wang(汪卫华)
    Chin. Phys. B, 2021, 30 (1): 018101.   DOI: 10.1088/1674-1056/abc54a
    Abstract99)   HTML0)    PDF (902KB)(107)      
    Strain glass is a frozen short-range strain ordered state found in shape memory alloys recently, which exhibits novel properties around the ideal glass transition temperature T0. However, the T0 of current strain glass systems is still very low, limiting their potential applications and experimental studies. In this paper, we reported two new strain glass systems with relatively high T0. In Ti50Au50-xCrx alloys, the strain glass appears at x=25, and exhibits a T0 of 251 K, while in Ti50Pt50-yFey alloys, the strain glass takes place at y=30, and shows a T0 of 272 K. Both of them are comparable with the highest T0 value reported so far. Moreover, the phase diagrams of main strain glass systems in Ti-based alloys were summarized. It is found that the influence of the martensitic transformation temperature of the host alloy on the T0 of the strain glass is limited. This work may help to design new strain glass systems with higher T0 above ambient temperature.
    Edge-and strain-induced band bending in bilayer-monolayer Pb2Se3 heterostructures
    Peng Fan(范朋), Guojian Qian(钱国健), Dongfei Wang(王东飞), En Li(李恩), Qin Wang(汪琴), Hui Chen(陈辉), Xiao Lin(林晓), and Hong-Jun Gao(高鸿钧)
    Chin. Phys. B, 2021, 30 (1): 018105.   DOI: 10.1088/1674-1056/abcf92
    Abstract113)   HTML0)    PDF (1091KB)(125)      
    By using scanning tunneling microscope/microscopy (STM/STS), we reveal the detailed electronic structures around the sharp edges and strained terraces of lateral monolayer-bilayer Pd2Se3 heterostructures. We find that the edges of such heterostructures are well-defined zigzag type. Band bending and alignment are observed across the zigzag edge, forming a monolayer-bilayer heterojunction. In addition, an n-type band bending is induced by strain on a confined bilayer Pd2Se3 terrace. These results provide effective toolsets to tune the band structures in Pd2Se3-based heterostructures and devices.
    Structural and electrical transport properties of Cu-doped Fe1 -xCuxSe single crystals
    He Li(李贺), Ming-Wei Ma(马明伟), Shao-Bo Liu(刘少博), Fang Zhou(周放), and Xiao-Li Dong(董晓莉)
    Chin. Phys. B, 2020, 29 (12): 127404.   DOI: 10.1088/1674-1056/abc3af
    Abstract406)   HTML    PDF (859KB)(512)      
    We report the structural and electrical transport properties of Fe1 -xCuxSe (x = 0, 0.02, 0.05, 0.10) single crystals grown by a chemical vapor transport method. Substituting Cu for Fe suppresses both the nematicity and superconductivity of FeSe single crystal, and provokes a metal-insulator transition. Our Hall measurements show that the Cu substitution also changes an electron dominance at low temperature of un-doped FeSe to a hole dominance of Cu-doped Fe1 -xCuxSe at x = 0.02 and 0.1, and reduces the sign-change temperature (TR) of the Hall coefficient (R H).
ISSN 1674-1056   CN 11-5639/O4

Current issue

, Vol. 30, No. 4

Previous issues

1992 - present