Related papers: Axionic Band Topology in Inversion-Symmetric Weyl-…
In a slab geometry with large surface-to-bulk ratio, topological surface states such as Fermi arcs for Weyl or Dirac semimetals may dominate their low-energy properties. We investigate the collective charge oscillations in such systems,…
The roton-triggered charge-density-wave (CDW)is widely studied in fractional quantum Hall (FQH) and fractional Chern insulator (FCI) systems, and there also exist field theoretical and numerical realizations of continuous transition from…
Transition metal dichalcogenides (TMDs), whether in bulk or in monolayer form, exhibit a rich variety of charge-density-wave (CDW) phases and stronger periodic lattice distortions. While the actual role of nesting has been under debate, it…
We study the problem of phase transitions from 3D topological to normal insulators without inversion symmetry. In contrast with the conclusions of some previous work, we show that a Weyl semimetal always exists as an intermediate phase…
Charge density wave (CDW) instability drastically affects the surface electron spectrum of a Weyl semimetal. We show that in the CDW phase, the Fermi arcs reconnect into either closed Fermi loops or Frieze patterns traversing the…
Topological semimetals are gapless states of matter which have robust and unique electromagnetic responses and surface states. In this paper, we consider semimetals which have point like Fermi surfaces in various spatial dimensions…
Following the intense studies on topological insulators, significant efforts have recently been devoted to the search for gapless topological systems. These materials not only broaden the topological classification of matter but also…
At partial filling of a flat band, strong electronic interactions may favor gapped states harboring emergent topology with quantized Hall conductivity. Emergent topological states have been found in partially filled Landau levels and…
The combination of non-trivial band topology and symmetry breaking phases gives rise to novel quantum states and phenomena such as topological superconductivity, quantum anomalous Hall effect and axion electrodynamics. Evidence of…
Weyl nodes come in pairs of opposite chirality. For broken time reversal symmetry (TR) they are displaced in momentum space by $\bf{Q}$ and the anomalous DC Hall conductivity $\sigma_{xy}$ is proportional to $\bf{Q}$ at charge neutrality.…
Weyl semimetals are conductors whose low-energy bulk excitations are Weyl fermions, whereas their surfaces possess metallic Fermi arc surface states. These Fermi arc surface states are protected by a topological invariant associated with…
We report experimental evidence of charge density wave (CDW) transition in monolayer 1T-VTe$_2$ film. 4$\times$4 reconstruction peaks are observed by low energy electron diffraction below the transition temperature $T_{CDW}$ = 186 K.…
We develop the mean-field theory of a charge-density wave (CDW) state in magnetic field and study the properties of this state below the transition temperature. We show that the CDW state with shifted wave vector in high magnetic field…
We investigated phase defects in a quasi-one-dimensional commensurate charge density wave (CDW) system, an In atomic wire array on Si(111), using low temperature scanning tunneling microscopy. The unique four-fold degeneracy of the CDW…
The interplay between magnetic ordering and band topology has emerged as a fertile ground for discovering novel quantum states with profound implications for fundamental physics and next-generation electronics. Here, we theoretically…
We investigate the charge and spin transport properties of a Weyl semimetal under an external magnetic field using a low-energy effective theory. By performing a chiral transformation, we remove the axial term from the fermionic Lagrangian,…
Using first-principles calculation methods, we reveal a series of phase transitions as a function of electron doping in single-layer 1T$'$-MoTe$_2$ and 1T$'$-WTe$_2$ exhibiting quantum spin Hall (QSH) edge states without doping. As…
Following the discovery of topological insulators (TIs), topological Dirac/Weyl semimetal has attracted much recent interest. A prevailing mechanism for the formation of Weyl points is by breaking time-reversal symmetry (TRS) or spatial…
In this study, we investigate the localized surface plasmon modes of a sub-wavelength spherical nanoparticle composed of a Weyl semimetal, taking into account the axion modification of electrodynamics. We derive analytical solutions for…
Axion insulators are 3D magnetic higher-order topological insulators protected by inversion-symmetry that exhibit hinge-localized chiral channels and induce quantized topological magnetoelectric effects. Recent research has suggested that…