Related papers: Berry-dipole Semimetals

The study of topological properties in magnetic materials has long been one of the forefront research areas in condensed matter physics. CrSb, as a prototypical candidate material for altermagnetism, has attracted significant attention due…

Optical lattices play a versatile role in advancing our understanding of correlated quantum matter. The recent implementation of orbital degrees of freedom in chequerboard and hexagonal optical lattices opens up a new thrust towards…

Featuring exotic quantum transport and surface states, topological semimetals can be classified into nodal-point, nodal-line, and nodal-surface semimetals according to the degeneracy and dimensionality of their nodes. However, a topological…

Topological properties lie at the heart of many fascinating phenomena in solid state systems such as quantum Hall systems or Chern insulators. The topology can be captured by the distribution of Berry curvature, which describes the geometry…

Hopf-link semimetals exhibit exotic gapless band structures with fascinating topological properties, which have never been observed in nature. Here we demonstrate nodal lines with topological form of Hopf-link chains in artificial…

We study a new class of non-Hermitian topological phases in three dimension in the absence of any symmetry, where the topological robust band degeneracies are Hopf-link exceptional lines. As a concrete example, we investigate the…

We show that excitons forming between moir\'e flat Chern bands possess a substantial electric dipole moment comparable to the moir\'e lattice parameter times the elementary charge ($\sim10^2$ Debye). At a hole filling factor of one in…

We propose a topological quantum phase transition for quantum states with different Berry phases in hole-doped III-V semiconductor quantum wells with bulk and structure inversion asymmetry. The Berry phase of the occupied Bloch states can…

We construct two-band topological semimetals in four dimensions using the unstable homotopy of maps from the three-torus $T^3$ (Brillouin zone of a 3D crystal) to the two-sphere $S^2$. Dubbed ``Hopf semimetals'', these gapless phases…

Chiral quasiparticles in Bernal-stacked bilayer graphene have valley-contrasting Berry phases of 2{\pi}. This nontrival topological structure, associated with the pseudospin winding along a closed Fermi surface, is responsible for various…

Magnetic topological materials and their physical signatures are a focus of current research. Here, by first-principles calculations and symmetry analysis, we reveal topological semimetal states in an existing antiferromagnet ThMn2Si2.…

In topological materials, Berry curvature leads to intrinsic Hall responses. Focusing on time-reversal symmetric systems with broken inversion symmetry, a spontaneoous (zero magnetic field) Hall effect is expected to develop under an…

We demonstrate that the physical reason for the nontrivial topological properties of Dirac semimetals $A_3 Bi$ (A=Na,K,Rb) is connected with a discrete symmetry of the low-energy effective Hamiltonian. By making use of this discrete…

Topologically non-trivial electronic structures can give rise to a range of unusual physical phenomena, and the interplay of band topology with other effects such as electronic correlations and magnetism requires further exploration. The…

We have observed the Berry phase effect associated with interband coherence in topological surface states (TSSs) using two-color high-harmonic spectroscopy. This Berry phase accumulates along the evolution path of strong field-driven…

Plasmons, the collective oscillations of interacting electrons, possess emergent properties that dramatically alter the optical response of metals. We predict the existence of a new class of plasmons -- chiral Berry plasmons (CBPs) -- for a…

We investigate the nonlinear Hall responses in tunable two-dimensional Dirac materials. In particular, we study quantum geometry-driven second and third order non-linear responses in a time-reversal symmetric Dirac semimetal that can host…

Topologically non-trivial states characterized by Berry curvature appear in a number of materials ranging from spin-orbit-coupling driven topological insulators to graphene. In multivalley conductors, such as mono- and bilayer graphene,…

The non-linear generalization of the Hall effect has recently gained much attention, with a rapidly growing list of non-centrosymmetric materials that display higher-order Hall responses under time-reversal invariant conditions. The…

Under broken time reversal symmetry such as in the presence of external magnetic field or internal magnetization, a transverse voltage can be established in materials perpendicular to both longitudinal current and applied magnetic field,…