Related papers: Symmetry-Protected Ideal Type-II Weyl Phonons in C…
Weyl semimetals exhibitinging the topologically nontrivial touching points in electronic band dispersion of solids pave the wave way to novel electronic devices and functionalities. Here, we demonstrate the signature of topologically…
Given the importance of crystal symmetry for the emergence of topological quantum states, we have studied, as exemplified in NbNiTe2, the interplay of crystal symmetry, atomic displacements (lattice vibration), band degeneracy, and band…
Ideal Weyl points, which are related by symmetry and thus reside at the same frequency, could promote the deep development and utilization of the Weyl physics. Although the ideal type-I Weyl points have been achieved in photonic crystals,…
Weyl points are often believed to appear in pairs with opposite chirality. In this work, we show by first-principles calculations and symmetry analysis that single Weyl phonons with linear dispersion and double Weyl phonons with quadratic…
Topological states of electrons and photons have attracted significant interest recently. Topological mechanical states also being actively explored, have been limited to macroscopic systems of kHz frequency. The discovery of topological…
Ideal Weyl semimetals with all Weyl nodes exactly at the Fermi level and no coexisting trivial Fermi surfaces in the bulk, similar to graphene, could feature deep physics such as exotic transport phenomena induced by the chiral anomaly.…
Topological Weyl semimetal (TWS) is a metal, where low energy excitations behave like Weyl fermions of high-energy physics. It was recently shown that due to the lower symmetry of condensed matter systems, they can realize two distinct…
Unconventional Weyl phonons with higher topological charges in crystalline solids have attracted increasing attention. By symmetry analysis and low-energy $k.p$ effective Hamiltonian, we propose the symmetry enforced triple hourglass Weyl…
The selective excitation of coherent phonons provides unique capabilities to control fundamental properties of quantum materials on ultrafast time scales. For instance, in the presence of strong electron-phonon coupling, the electronic band…
The discovery of Weyl semimetals represents a significant advance in topological band theory. They paradigmatically enlarged the classification of topological materials to gapless systems while simultaneously providing experimental evidence…
Magnetic topological materials have recently drawn significant importance and interest, due to their topologically nontrivial electronic structure within spontaneous magnetic moments and band inversion. Based on first-principles…
Novel quasi two dimensional typically layered semimetals offer a unique opportunity to control the density and even the topology of the electronic matter. In intercalated MoTe2 type II Weyl semimetal the tilt of the dispersion relation…
We show that compounds in a family that possess time-reversal symmetry and share a non-centrosymmetric cubic structure with the space group F-43m (No. 216) host robust ideal Weyl semi-metal fermions with desirable topologically protected…
Quantum topological materials, exemplified by topological insulators, three-dimensional Dirac semimetals and Weyl semimetals, have attracted much attention recently because of their unique electronic structure and physical properties. Very…
Unconventional Weyl points (WPs), carrying topological charge 2 or higher, possess interesting properties different from ordinary charge-1 WPs, including multiple Fermi arcs that stretch over a large portion of the Brillouin zone. Thus far,…
Recent breakthrough in search for the analogs of fundamental particles in condensed matter systems lead to experimental realizations of 3D Dirac and Weyl semimetals. Weyl state can be hosted either by non-centrosymmetric or magnetic…
Weyl points (WPs), as nodal degenerate points in three-dimensional (3D) momentum space, are ideal if they are symmetry-related, well-separated, residing at the same energy and far from the nontopological bands. Although type-II WPs show…
Unconventional topological quasiparticles have recently garnered significant attention in the realm of condensed matter physics. Here, based on first-principles calculations and symmetry analysis, we reveal the coexistence of multiple types…
Realizing Weyl semimetals (WSMs) with the minimal number of Weyl points (WPs) fundamentally simplifies extracting intrinsic topological responses. While a minimum of four conventional ($|C|=1$) WPs in nonmagnetic crystals is…
By using \emph{ab initio} calculations and symmetry analysis, we define a new class of Weyl phonons, i.e., isolated Weyl phonons (IWPs), which are characterized by Chern number $\pm$2 or $\pm$4 in their acoustic phononic spectra and…