Berry curvature dipole current in transition metal dichalcogenides family

TL;DR

This paper investigates the quantum nonlinear Hall effect in 2D transition metal dichalcogenides, showing how Berry curvature dipoles induce transverse currents under electric fields, with potential for experimental observation.

Contribution

It demonstrates the presence and controllability of Berry curvature dipoles in various phases of TMDCs using ab initio methods, highlighting their role in nonlinear Hall effects.

Findings

Monolayer Td-structured TMDCs exhibit finite Berry curvature dipoles.

Strain and electric fields induce Berry curvature dipoles in 1H and 1T' phases.

Finite Berry curvature dipoles lead to nonlinear Hall responses.

Abstract

We study the quantum nonlinear Hall effect in two-dimensional materials with time-reversal symmetry. When only one mirror line exists, a transverse charge current occurs in second-order response to an external electric field, as a result of the Berry curvature dipole in momentum space. Candidate 2D materials to observe this effect are two-dimensional transition-metal dichalcogenides~(TMDCs). First we use an ab initio based tight-binding approach to demonstrate that monolayer $T_d$-stricture TMDCs exhibit a finite Berry curvature dipole. In the $1H$ and $1T'$ phase of TMDCs, we show the emergence of finite Berry curvature dipole with the application of strain and electrical displacement field respectively.