Related papers: Two-dimensional Dirac semiconductor and its materi…
Crystalline symmetries can generate exotic band-crossing features, which can lead to unconventional fermionic excitations with interesting physical properties. We show how a cubic Dirac point---a four-fold-degenerate band-crossing point…
Two-dimensional (2D) materials, especially their most prominent member, graphene, have greatly influenced many scientific areas. Moreover, they have become a base for investigating the relativistic properties of condensed matter within the…
Filling-enforced Dirac semimetals, or those required at specific fillings by the combination of crystalline and time-reversal symmetries, have been proposed and discovered in numerous materials. However, Dirac points in these materials are…
We investigate the phase diagram of moir\'e double bilayer transition metal dichalcogenides with ABBA stacking as a function of twist angle and applied pressure. At hole filling $\nu = 2$ per moir\'e unit cell, the noninteracting system…
We theoretically propose a design for two-dimensional Dirac semimetals using a bilayer-modified Bernevig-Hughes-Zhang (BHZ) model. By introducing new sites into the BHZ model, we engineer flat bands at the Fermi energy. In the bilayer…
We propose to realize Dirac states in an inclined two-dimensional Su-Schrieffer-Heeger model on a square lattice. We show that a pair of Dirac points protected by space-time inversion symmetry appear in the semimetal phase. The locations of…
A single Dirac cone on the surface is the hallmark of three-dimensional (3D) topological insulators, where the double degeneracy at the Dirac point is protected by time-reversal symmetry and the spin-splitting away from the point is…
Semi-Dirac fermions are known to exist at the critical points of topological phase transitions requiring fine-tuning of the parameters. We show that robust semi-Dirac points can appear in a heterostructure consisting of superconducting…
We report the experimental realization of two-dimensional (2D) weak topological insulator (WTI) in spinless Su-Schrieffer-Heeger circuits with parity-time and chiral symmetries. Strong and weak $\mathbb{Z}_2$ topological indexes are adopted…
Dirac semimetals show nontrivial physical properties and can host exotic quantum states like Weyl semimetals and topological insulators under suitable external conditions. Here, by combining angle-resolved photoemission spectroscopy…
Superconductivity becomes more interesting when it encounters dimensional constraint or topology, because it is of importance for exploring exotic quantum phenomena or developing superconducting electronics. Here we report the coexistence…
We analyze the topological properties of a chiral ${p}+i{p}$ superconductor for a two-dimensional metal/semimetal with four Dirac points. Such a system has been proposed to realize second-order topological superconductivity and host corner…
Based on first-principles calculations and symmetry analysis, we propose that a transition metal rutile oxide, in particular $\beta'$-PtO$_2$, can host a three-dimensional topological Dirac semimetal phase. We find that $\beta'$-PtO$_2$…
We study a class of Dirac semimetals that feature an eightfold-degenerate double Dirac point. We show that 7 of the 230 space groups can host such Dirac points and argue that they all generically display linear dispersion. We introduce an…
Topological insulators are distinguished from normal insulators by their bulk insulating gap and odd number of surface states connecting the inverted conduction and valence bands and showing Dirac cones at the time-reversal invariant points…
There has been an upsurge in the discovery of topological quantum materials, where various topological insulators and semimetals have been theoretically predicted and experimentally observed. However, only very few of them contains silicon,…
Silicene, an analogue of graphene, was so far predicted to be the only two-dimensional silicon (2D-Si) with massless Dirac fermions. Here we predict a brand new 2D-Si Dirac semimetal, which we name siliconeet [silik'ni:t]. Unexpectedly, it…
Thin flakes of black phosphorus (BP) are a two-dimensional (2D) semiconductor whose energy gap is predicted being sensitive to the number of layers and external perturbations. Very recently, it was found that a simple method of potassium…
Realizing stable two-dimensional (2D) Dirac points against spin-orbit coupling (SOC) has attracted much attention because it provides a platform to study the unique transport properties. In previous work, Young and Kane [Phys. Rev. Lett.…
Surface Dirac cones in three-dimensional topological insulators have generated tremendous and enduring interest for almost two decades owing to hosting a multitude of exotic properties. In this work, we unveil the existence of two types of…