Related papers: Quantum spin Hall effect on the porphyrin lattice
This is a joint publication with the Letter by H. Huang and F. Liu [Phys. Rev. Lett. 121, 126401 (2018)]. In this work, we propose the spin Bott index to identify the quantum spin Hall (QSH) state in both crystalline and non-periodic…
We study the phase transitions of bosonic $\nu=1/2$ fractional quantum Hall (FQH) effect in different topological lattice models under the interplay of onsite periodic potential and Hubbard repulsion. Through exact diagonalization and…
We study the quantum phases of spinless fermion at one-third filling on a Kagome lattice featuring a quadratic band touching Fermi point. In the presence of weak first and second nearest-neighbor repulsive interactions ($V_1$ and $V_2$), we…
We prove a Lieb-Schultz-Mattis theorem for the quantum spin Hall effect (QSHE) in two-dimensional $\pi$-flux models. In the presence of time reversal, $U(1)$ charge conservation and magnetic translation (with $\pi$-flux per unit cell)…
Quantum anomalous Hall (QAH) effect in magnetic topological insulator (TI) is a novel transport phenomenon in which the Hall resistance reaches the quantum plateau in the absence of external magnetic field. Recently, this exotic effect has…
The quantum anomalous Hall (QAH) effect has recently been realized in thin films of intrinsic magnetic topological insulators (IMTIs) like MnBi$_2$Te$_4$. Here we point out that that the QAH gaps of these IMTIs can be optimized, and that…
Quantum spin Hall insulators (QSHIs), also known as two-dimensional topological insulators, have emerged as an unconventional class of quantum states with insulating bulk and conducting edges originating from nontrivial inverted band…
We review our recent theoretical works on the the quantum spin Hall effect. First we compare edge states in various 2D systems, and see whether they are robust or fragile against perturbations. Through the comparisons we see the robust…
We investigate an unconventional topological phase transition that occurs in quantum spin Hall (QSH) systems when applying an external in-plane magnetic field. We show that this transition between QSH and trivial insulator phases is…
We theoretically propose the occurrence of a quantum spin Hall (QSH) and a second order topological phase transition (TPT) driven by electron-phonon (e-p) coupling in a pseudospin-$1$ fermionic system on an $\alpha$-$T_3$ lattice. Our model…
The quantum spin Hall (QSH) effect in the DC regime, which has been intensively researched, relies on the existence of symmetry-protected edge states. Here, we demonstrate that a QSH system behaves quite differently in response to an…
The substrate-induced topological phase transition of silience is a formidable obstacle for developing silicene-based materials and devices for compatibility with current electronics by using its topologically protected dissipationless edge…
The field of topological insulators (TI) was sparked by the prediction of the quantum spin Hall effect (QSHE) in time reversal invariant systems, such as spin-orbit coupled monolayer graphene. Ever since, a variety of monolayer crystals…
Quantum spin Hall (QSH) state of matter has a charge excitation bulk bandgap and a pair of gapless spin-filtered edge-states, which can support backscattering-free transport. Bilayer phosphorene possesses a large tunable bandgap and high…
Topological insulators are bulk electronic insulators which possess symmetry protected gapless modes on their surfaces. Breaking the symmetries that underlie the gapless nature of the surface modes is predicted to give rise to exotic new…
Inspired by experiments on magic angle twisted bilayer graphene, we present a lattice mean-field model for the quantum anomalous Hall effect in a moir\'e setting. Our hopping model thus provides a simple route to a moir\'e Chern insulator…
In magnetic topological phases of matter, the quantum anomalous Hall (QAH) effect is an emergent phenomenon driven by ferromagnetic doping, magnetic proximity effects and strain engineering. The realization of QAH states with multiple…
Non-interacting topological states of matter can be realized in band insulators with intrinsic spin-orbital couplings as a result of the nontrivial band topology. In recent years, the possibility of realizing novel interaction-driven…
Using tight-binding models and first-principles calculations, we demonstrate the possibility to achieve a quantum anomalous Hall (QAH) phase on a two-dimensional square lattice, which can be realized in monolayers of double perovskites. We…
Topological quantum phase transition in electron gas systems is an enthralling phenomena. This phase transition has a unique property in that it is associated with a quantum phase transition point, which separates different regions with…