Now showing items 1-20 of 21

    • (111) Surface States of SnTe 

      Shi, Yin; Wu, Meng; Zhang, Fan; Feng, Ji (2014-12--0)
      The characterization and applications of topological insulators depend critically on their protected surface states, which, however, can be obscured by the presence of trivial dangling bond states. Our first-principle ...
    • Buckled Honeycomb Lattice Materials and Unconventional Magnetic Responses 

      Yang, S. A.; Pan, H.; Zhang, Fan (Royal Society of Chemistry, 2015-09-24)
      We study the magnetic response of two-dimensional buckled honeycomb-lattice materials. The buckling breaks the sublattice symmetry, enhances the spin-orbit coupling, and allows the tuning of a topological quantum phase ...
    • Chirality-Dependent Hall Effect in Weyl Semimetals 

      Yang, Shengyuan A.; Pan, Hui; Zhang, Fan (Amer Physical Soc, 2015-10-09)
      We generalize a semiclassical theory and use the argument of angular momentum conservation to examine the ballistic transport in lightly doped Weyl semimetals, taking into account various phase-space Berry curvatures. We ...
    • Circular Dichroism and Radial Hall Effects in Topological Materials 

      Liu, Ying; Yang, Shengyuan A.; Zhang, Fan (Amer Physical Soc, 2018-10-22)
      Under symmetry breaking, a three-dimensional nodal-line semimetal can turn into a topological insulator or Weyl semimetal, accompanied by the generation of momentum-space Berry curvature. We develop a theory that unifies ...
    • Critical Behavior of Four-Terminal Conductance of Bilayer Graphene Domain Walls 

      Wieder, Benjamin J.; Zhang, Fan; Kane, C. L. (2015-08-24)
      Bilayer graphene in a perpendicular electric field can host domain walls between regions of reversed field direction or interlayer stacking. The gapless modes propagating along these domain walls, while not strictly ...
    • Dirac and Weyl Superconductors in Three Dimensions 

      Yang, S. A.; Pan, H.; Zhang, Fan (American Physical Society, 2014-07-21)
      We introduce the concept of three-dimensional Dirac (Weyl) superconductors (SC), which have protected bulk fourfold (twofold) nodal points and surface Majorana arcs at zero energy. We provide a sufficient criterion for ...
    • Energy Gaps and Layer Polarization of Integer and Fractional Quantum Hall States in Bilayer Graphene 

      Shi, Yanmeng; Lee, Yongjin; Che, Shi; Pi, Ziqi; Espiritu, Timothy; Stepanov, Petr; Smirnov, Dmitry; Lau, Chun Ning; Zhang, Fan (American Physical Society, 2016-02-05)
      Owing to the spin, valley, and orbital symmetries, the lowest Landau level in bilayer graphene exhibits multicomponent quantum Hall ferromagnetism. Using transport spectroscopy, we investigate the energy gaps of integer ...
    • First-Principles Study of Metal-Graphene Edge Contact for Ballistic Josephson Junction 

      Lee, Yeonghun; Hwang, Jeongwoon; Zhang, Fan; Cho, Kyeongjae (American Physical Society, 2019-06-05)
      Edge-contacted superconductor-graphene-superconductor Josephson junctions have been utilized to realize topological superconductivity, and have shown superconducting signatures in the quantum Hall regime. We perform ...
    • Observation of Acoustic Valley Vortex States and Valley-Chirality Locked Beam Splitting 

      Ye, Liping; Qiu, Chunyin; Lu, Jiuyang; Wen, Xinhua; Shen, Yuanyuan; Ke, Manzhu; Zhang, Fan; Liu, Zhengyou (2017-05-23)
      We report an experimental observation of the classical version of valley polarized states in a two-dimensional hexagonal sonic crystal. The acoustic valley states, which carry specific linear momenta and orbital angular ...
    • Odd-Integer Quantum Hall States and Giant Spin Susceptibility in P -Type Few-Layer WSe₂ 

      Xu, S.; Shen, J.; Long, G.; Wu, Z.; Bao, Zhi-qiang; Liu, Cheng-Cheng; Xiao, X.; Han, T.; Lin, J.; Wu, Y.; Lu, H.; Hou, J.; An, L.; Wang, Y.; Cai, Y.; Ho, K. M.; He, Y.; Lortz, R.; Zhang, Fan; Wang, N. (American Physical Society, 2017-02-10)
      We fabricate high-mobility p-type few-layer WSe₂ field-effect transistors and surprisingly observe a series of quantum Hall (QH) states following an unconventional sequence predominated by odd-integer states under a moderate ...
    • Perfect Valley Filter in a Topological Domain Wall 

      Pan, Hui; Li, Xin; Zhang, Fan; Yang, Shengyuan A. (Amer Physical Soc, 2015-07-07)
      We propose a realization of perfect valley filters based on the chiral domain-wall channels between a quantum anomalous Hall insulator and a quantum valley Hall insulator. Uniquely, all these channels reside in the same ...
    • Quantum Parity Hall Effect in Bernal-Stacked Trilayer Graphene 

      Stepanov, P.; Barlas, Y.; Che, S.; Myhro, K.; Voigt, G.; Pi, Z.; Watanabe, K.; Taniguchi, T.; Smirnov, D.; Zhang, Fan; Lake, R. K.; MacDonald, A. H.; Lau, C. N. (National Academy of Sciences, 2019-05-03)
      The quantum Hall effect has recently been generalized from transport of conserved charges to include transport of other approximately conserved-state variables, including spin and valley, via spin- or valley-polarized ...
    • Spatially Correlated MIMO Broadcast Channel with Partially Overlapping Correlation Eigenspaces 

      Zhang, Fan; Nosratinia, Aria
      The spatially correlated MIMO broadcast channel has grown in importance due to emerging interest in massive MIMO and mm-wave communication, but much about this channel remains unknown. In this paper, we study a two-user ...
    • Structured Weyl Points in Spin-Orbit Coupled Fermionic Superfluids 

      Xu, Yong; Zhang, Fan; Zhang, Chuanwei (American Physical Society, 2015-12-30)
      We demonstrate that a Weyl point, widely examined in 3D Weyl semimetals and superfluids, can develop a pair of nondegenerate gapless spheres. Such a bouquet of two spheres is characterized by three distinct topological ...
    • SU(3) Quantum Hall Ferromagnetism in SnTe 

      Li, X.; Zhang, Fan; MacDonald, A. H. (American Physical Society, 2016-01-15)
      The (111) surface of SnTe hosts one isotropic Γ-centered and three degenerate anisotropic M-centered Dirac surface states. We predict that a nematic phase with spontaneously broken C₃ symmetry will occur in the presence ...
    • Topological Majorana Two-Channel Kondo Effect 

      Bao, Zhi-qiang; Zhang, Fan (American Physical Society, 2017-10-31)
      A one-dimensional time-reversal-invariant topological superconductor hosts a Majorana Kramers pair at each end, where time-reversal symmetry acts as a supersymmetry that flips local fermion parity. We examine the transport ...
    • Topological Triply Degenerate Points Induced by Spin-Tensor- Momentum Couplings 

      Hu, Haiping; Hou, Junpeng; Zhang, Fan; Zhang, Chuanwei
      The recent discovery of triply degenerate points (TDPs) in topological materials has opened a new perspective toward the realization of novel quasiparticles without counterparts in quantum field theory. The emergence of ...
    • Topological Triply Degenerate Points Induced by Spin-Tensor-Momentum Couplings 

      Hu, Haiping; Hou, Junpeng; Zhang, Fan; Zhang, Chuanwei
      The recent discovery of triply degenerate points (TDPs) in topological materials has opened a new perspective toward the realization of novel quasiparticles without counterparts in quantum field theory. The emergence of ...
    • Valley Topological Phases In Bilayer Sonic Crystals 

      Lu, Jiuyang; Qiu, Chunyin; Deng, Weiyin; Huang, Xueqin; Li, Feng; Zhang, Fan; Chen, Shuqi; Liu, Zhengyou
      Recently, the topological physics in artificial crystals for classical waves has become an emerging research area. In this Letter, we propose a unique bilayer design of sonic crystals that are constructed by two layers of ...
    • Weak Topological Insulators and Composite Weyl Semimetals: β-Bi₄Χ₄ (Χ = Br, I) 

      Liu, Cheng-Cheng; Zhou, Jin-Jian; Yao, Yugui; Zhang, Fan (Amer Physical Soc, 2016-02-09)
      While strong topological insulators (STIs) were experimentally realized soon after they were theoretically predicted, a weak topological insulator (WTI) has yet to be unambiguously confirmed. A major obstacle is the lack ...