相关论文: Tetragonal Mexican-Hat Dispersion and Switchable H…

Van der Waals (vdW) heterostructures, which combine bi-dimensional materials of different properties, enable a range of quantum phenomena. Here, we present a comparative study between the electronic properties of mono- and bi-layer of…

Weyl semi-metals are three dimensional generalizations of graphene with point-like Fermi surfaces. Their linear electronic dispersion leads to a window in the particle-hole excitation spectrum which allows for undamped propagation of…

We present a theoretical investigation of the electronic band structure and optical properties of a two-dimensional anisotropic semimetal that is described by a tilted semi-Dirac type spectrum with a pair of Weyl nodes. We observe that a…

Interlayer sliding degrees of freedom often determine the physical properties of two-dimensional (2D) materials. In graphene, for instance, the metastable rhombohedral stacking arrangement hosts correlated and topological electronic phases,…

A signature property of Weyl semimetals is the existence of topologically protected surface states - arcs in momentum space that connect Weyl points in the bulk. However, the presence of bulks states makes detection of surface contributions…

The study of the Weyl fermions and Kagome bands has recently attracted significant attention in condensed matter physics. However, realizing of perfect Weyl semimetals and double Kagome bands remains challenging. Here, we report a new class…

Quantum spin Hall (QSH) insulator materials feature topologically protected edge states that can drastically reduce dissipation and are useful for the next-generation electronics. However, the nonvolatile control of topological edge state…

Chromium ditelluride, CrTe$_2$, is an attractive candidate van der Waals material for hosting 2D magnetism. However, how the room-temperature ferromagnetism of the bulk evolves as the sample is thinned to the single-layer limit has proved…

Weyl semimetals are a new paradigmatic topological phase of matter featuring a gapless spectrum. One of its most distinctive features is the presence of Fermi arc surface states. Here, we report on atomistic simulations of the dc…

Application of a perpendicular electric field induces a band gap in bilayer graphene, and it also creates a "Mexican hat" structure in the dispersion relation. This structure has unusual implications for the hydrogen-like bound state of an…

We present a comprehensive first-principles investigation of a novel carbon allotrope characterized by quasi-tetragonal atomic motifs and quasi-two-dimensional structural behavior. Structural analysis reveals an open framework composed of…

Extending the Dirac physics of two-dimensional (2D) graphene into three dimensions (3D) carbon allotropes with higher-dimensional band degeneracies remains a central challenge in topological materials science. Here, we propose a general…

By means of $ab \ initio$ band structure methods and model Hamiltonians we investigate the electronic, spin and topological properties of four monopnictides crystallizing in body centered tetragonal structure. We show that the Weyl bands…

Weyl fermions are powerful yet simple entities that connect geometry, topology, and physics. While their existence as fundamental particles is still uncertain, growing evidence shows they emerge as quasiparticles in special materials called…

We report a comprehensive neutron scattering study on the spin excitations in the magnetic Weyl semimetal Co$_3$Sn$_2$S$_2$ with quasi-two-dimensional structure. Both in-plane and out-of-plane dispersions of the spin waves are revealed in…

Nodal-line metals and semimetals, as interesting topological states of matter, have been mostly studied in nonmagnetic materials. Here, based on first-principles calculations and symmetry analysis, we predict that fully spin-polarized Weyl…

Altermagnetism -a magnetic state characterized by spin-polarized electronic bands at zero net magnetization- offers a promising route for next-generation spintronic devices. In two-dimensional (2D) magnets, twist engineering enables its…

Controlling the magnetic anisotropy of ferromagnetic materials plays a key role in magnetic switching devices and spintronic applications. Examples of spin-orbit torque devices with different magnetic anisotropy geometries (in-plane or…

Smooth interfaces of topological systems are known to host massive surface states along with the topologically protected chiral one. We show that in Weyl semimetals these massive states, along with the chiral Fermi arc, strongly alter the…

Weyl superconductivity or superfluidity, a fascinating topological state of matter, features novel phenomena such as emergent Weyl fermionic excitations and anomalies. Here we report that an anisotropic Weyl superfluid state can arise as a…