Related papers: Gate-tuned quantum Hall states in Dirac semimetal …
Very recently, in spite of various efforts in searching for two dimensional topological Dirac semimetals (2D TDSMs) in phosphorene, there remains a lack of experimentally efficient way to activate such phase transition and the underlying…
Quantum Hall ferromagnetic transitions are typically achieved by increasing the Zeeman energy through in-situ sample rotation, while transitions in systems with pseudo-spin indices can be induced by gate control. We report here a…
Combining the ability to prepare high-quality, intrinsic Bi$_2$Te$_3$ topological insulator thin films of low carrier density with in-situ protective capping, we demonstrate a pronounced, gate-tunable change in transport properties of…
Manipulating carrier density through gate effects, both in electrostatic charge storage and electrochemical intercalation mode, offers powerful control over material properties, although commonly restricted to ultra-thin films or van der…
In a low-disorder two-dimensional electron system, when two Landau levels of opposite spin or pseudospin cross at the Fermi level, the dominance of the exchange energy can lead to a ferromagnetic, quantum Hall ground state whose gap is…
Usually the quantum spin Hall states are expected to possess gapless, helical edge modes. Are there clean, non-interacting, quantum spin Hall states without gapless, edge modes? We show the generic, $n$-fold-symmetric, momentum planes of…
We report an observation of a topologically protected transport of surface carriers in a quasi-ballistic Cd3As2 nanowire.The nanowire is thin enough for the spin-textured surface carriers to form 1D subbands, demonstrating conductance…
We propose a new topological quantum state of matter---the two-dimensional (2D) Weyl half semimetal (WHS), which features 2D Weyl points at Fermi level belonging to a single spin channel, such that the low-energy electrons are described by…
The quantum Hall effect in graphene is regarded to be involving half-integer topological numbers associated with the massless Dirac particle, this is usually not apparent due to the doubling of the Dirac cones. Here we theoretically…
Using first principles calculations, we have demonstrated the creation of multiple quantum states, in the experimentally accessible metal organic framework BHT-Ni. Specifically, quantum spin Hall and quantum anomalous Hall states are…
Pulsed magnetic fields of up to 55T are used to investigate the transport properties of the topological insulator Bi_2Se_3 in the extreme quantum limit. For samples with a bulk carrier density of n = 2.9\times10^16cm^-3, the lowest Landau…
Charge density waves (CDWs) in two-dimensional (2D) materials have been a major focus of research in condensed matter physics for several decades due to their potential for quantum-based technologies. In particular, CDWs can induce a…
Three-dimensional (3D) topological Dirac semimetal, when thinned down to 2D few layers, is expected to possess gapped Dirac nodes via quantum confinement effect and concomitantly display the intriguing quantum spin Hall (QSH) insulator…
Unconventional features of relativistic Dirac/Weyl quasi-particles in topological materials are most evidently manifested in the 2D quantum Hall effect (QHE), whose variety is further enriched by their spin and/or valley polarization.…
Here we demonstrate the Shubnikov de Haas oscillation in high-quality Cd3As2 nanowires grown by a chemical vapor deposition approach. The dominant transport of topological Dirac fermions is evident by the nontrivial Berry phase in the…
We investigate the 3D quantum Hall effect in Weyl semimetals and elucidate a global picture of the edge states. The edge states hosting 3D quantum Hall effect are combinations of Fermi arcs and chiral bulk Landau levels parallel to the…
We study the quantum Hall effect of 2D electron gas in black phosphorus in the presence of perpendicular electric and magnetic fields. In the absence of a bias voltage, the external magnetic field leads to a quantization of the energy…
Nontrivial topology of Dirac (DSMs), Weyl (WSMs) and nodal line semimetals (NLSMs) are delineated by the novel band crossings near the Fermi level in the bulk and the appearance of exotic surface states. Among them, nodal line semimetals…
Quantum limit is quite easy to achieve once the band crossing exists exactly at the Fermi level ($E_F$) in topological semimetals. In multilayered Dirac fermion system, the density of Dirac fermions on the zeroth Landau levels (LLs)…
The parity anomalous semimetal is a topological state of matter characterized by its semi-metallic nature and a quantum Hall conductance of one-half $e^{2}/h$ ($e$ is the elementary charge and $h$ is the Planck constant). Here we…