Related papers: Quantum Spin Hall Effect in Inverted Type II Semic…
Conventional wisdom holds that, in the simplest time-reversal-symmetric setting, strongly coupling two QSH layers yields a trivial $\mathbb Z_2$ phase and no protected topological edge states. We demonstrate that, in a regime with…
We study the phase diagram of the inverted InAs/GaSb bilayer quantum wells. For small tunneling amplitude between the layers, we find that the system is prone to formation of an s-wave exciton condensate phase, where the spin-structure of…
We propose a scheme to realize time-reversal symmetry-broken quantum spin Hall insulators using bilayer honeycomb lattices, combining intrinsic spin-orbit coupling, C-type antiferromagnetic ordering, and staggered potentials. The C-type…
The hybridization gap in strained-layer InAs/InxGa1-xSb quantum spin Hall insulators (QSHIs) is significantly enhanced compared to binary InAs/GaSb QSHI structures, where the typical indium composition, x, ranges between 0.2 and 0.4. This…
The discovery of the quantum Hall (QH) effect led to the realization of a topological electronic state with dissipationless currents circulating in one direction along the edge of a two dimensional electron layer under a strong magnetic…
Quantum spin Hall insulators, recently realized in HgTe/(Hg,Cd)Te quantum wells, support topologically protected, linearly dispersing edge states with spin-momentum locking. A local magnetic exchange field can open a gap for the edge…
The search of new topological insulators that demonstrate the quantum anomalous Hall effect (QAHE) is a cutting-edge research topic in condensed matter physics and materials science. So far, the QAHE has been observed only in Cr-doped…
The quantum anomalous Hall effect (QAHE) is a robust topological phenomenon featuring quantized Hall resistance at zero magnetic field. We report the QAHE in a rhombohedral pentalayer graphene/monolayer WS2 heterostructure. Distinct from…
Electron correlation and topology are two central threads of modern condensed matter physics. Semiconductor moir\'e materials provide a highly tunable platform for studies of electron correlation. Correlation-driven phenomena, including the…
We consider a time reversal symmetry (TRS) broken Kane-Mele model superimposed with Haldane model and chart out the phase diagram using spin Chern number to investigate the fate of quantum anomalous Hall insulator (QAHI) and quantum spin…
We discuss the orbital effect of a tilted magnetic field on the quantum Hall effect in parabolic quantum wells. Many-body states realized at the fractional 1/3 and 1/2 filling of the second electronic subband are studied using finite-size…
Despite many years of efforts, attempts to reach the quantum regime of topological surface states (TSS) on an electrically tunable topological insulator (TI) platform have so far failed on binary TI compounds such as Bi2Se3 due to high…
The recent experimental observation of a potential fractional quantum spin Hall (FQSH) state in the twisted MoTe$_2$ system has sparked theoretical explorations at total filling $\nu_T=1$ of a pair of $C=\pm 1$ Chern bands from the two…
Quantum spin Hall (QSH) system can exhibit exotic spin transport phenomena, mediated by its topological edge states. Here a novel concept of bending strain engineering to tune the spin transport properties of a QSH system is demonstrated by…
We examine effects of inversion asymmetry of a GaAs/Al0.3Ga0.7As quantum well (QW) on electron-nuclear spin coupling in the fractional quantum Hall (QH) regime. Increasing the QW potential asymmetry at a fixed Landau-level filling factor…
The search for large gap quantum spin Hall (QSH) and quantum anomalous Hall (QAH) insulators is important both for fundamental and practical interests. The degenerate multi-orbitals $p_x,p_y$ in honeycomb lattice provides a paradigm for QSH…
In two-dimensional electron systems confined to GaAs quantum wells, as a function of either tilting the sample in magnetic field or increasing density, we observe multiple transitions of the fractional quantum Hall states (FQHSs) near…
Spin-momentum-locked edge states of quantum spin Hall insulators (QSHIs) provide a compelling platform for spintronic applications, owing to their intrinsic protection against backscattering from non-magnetic disorder. This protection…
While the helical character of the edge channels responsible for charge transport in the quantum spin Hall regime of a two-dimensional topological insulator is by now well established, an experimental confirmation that the transport in the…
We present magnetotransport measurements of a strongly hybridized inverted InAs/GaSb double quantum well. We find that the spin-orbit interaction leads to an appreciable spin-splitting of hole-like states, which form distinct Landau levels…