相关论文: Quantum oscillations between excitonic and quantum…

Applying electric or magnetic fields is widely used to not only create and manipulate topological states but also facilitate their observations in experiments. In this work, we show by first-principles calculations and topological analysis…

As the thickness of a three-dimensional (3D) topological insulator (TI) becomes comparable to the penetration depth of the surface states, quantum tunneling between surfaces turns their gapless Dirac electronic structure into a gapped…

Electrical currents in a quantum spin Hall insulator are confined to the boundary of the system. The charge carriers can be described as massless relativistic particles, whose spin and momentum are coupled to each other. While the helical…

We study, the interplay between topology and electron-electron interactions in the moir\'{e} MoTe\(_2\)/WSe\(_2\) heterobilayer. In our analysis we apply an effective two-band model with complex hoppings that incorporates the Ising-type…

The paired top and bottom Dirac surface states, each associated with a half-integer quantum Hall (QH) effect, and a resultant integer QH conductance ({\nu}e2/h), are hallmarks of a three-dimensional (3D) topological insulator (TI). In a…

In Mott insulators, the strong electron-electron Coulomb repulsion prevents metallicity and charge excitations are gapped. In dimensions greater than one, their spins are usually ordered antiferromagnetically at low temperatures.…

We show that moir\'e bands of twisted homobilayers can be topologically nontrivial, and illustrate the tendency by studying valence band states in $\pm K$ valleys of twisted bilayer transition metal dichalcogenides, in particular, bilayer…

We report the studies of high-quality HgTe/(Cd,Hg)Te quantum wells (QWs) with a width close to the critical one $d_c$, corresponding to the topological phase transition and graphene like band structure in view of their applications for…

We theoretically investigate a tight binding model of fermions hopping on the square-octagon lattice which consists of a square lattice with plaquette corners themselves decorated by squares. Upon the inclusion of second neighbor spin-orbit…

While two-dimensional topological insulators (2D TI) initiated the field of topological materials, only very few materials were discovered to date and the direct access to their quantum spin Hall edge states has been challenging due to…

Magnetic topological insulators (MTI) constitute a novel class of materials where the topologically protected band structure coexists with long-range ferromagnetic order, which can lead to the breaking of time-reversal symmetry (TRS),…

Using first principles techniques, we show that infrared optical response can be used to discriminate between the topological and the trivial phases of two-dimensional quantum spin Hall insulators (QSHI). We showcase germanene and…

Two-dimensional semiconducting moir\'e materials have emerged as a highly tunable platform for exploring novel quantum phenomena. Recently, tMoTe2 has attracted significant attentions due to the observation of the long-sought fractional…

Topological insulators are characterized by a nontrivial band topology driven by the spin-orbit coupling. To fully explore the fundamental science and application of topological insulators, material realization is indispensable. Here we…

The nature of a metal--insulator transition tuned by external gates in quantum Hall (QH) systems with point constrictions at integer bulk filling, as reported in recent experiments of Roddaro et al. [1], is addressed. We are particularly…

We numerically investigate the quantum phases and phase transition in a system made of two species of fermionic atoms that interact with each other via $s$-wave Feshbach resonance, and are subject to rotation or a synthetic gauge field that…

The quantum spin Hall (QSH) effect is the property of a new state of matter which preserves time-reversal, has an energy gap in the bulk, but has topologically robust gapless states at the edge. Recently, it has been shown that HgTe quantum…

We study a spinful, time-reversal symmetric lowest Landau level model for a flatband quantum spin Hall system at total filling fraction $\nu_\mathrm{T}=2/3$. Such models are relevant, e.g. for spin-valley locked moir\'e transition metal…

Formation of topological quantum phase on conventional semiconductor surface is of both scientific and technological interest. Here, we demonstrate epitaxial growth of 2D topological insulator, i.e. quantum spin Hall (QSH) state, on Si(111)…

Nonlinear Hall effect (NHE) can be generated via Berry curvature dipole (BCD) on nonequilibrium Fermi surface in a non-magnetic system without inversion symmetry.To achieve a large BCD, strong local Berry curvatures and their variation with…