Prediction of ferroelectricity-driven Berry curvature enabling charge- and spin-controllable photocurrent in tin telluride monolayers

TL;DR

This paper demonstrates that ferroelectricity in tin telluride monolayers induces a unique Berry curvature distribution, enabling controllable charge and spin photocurrents through manipulation of polarization and photon properties.

Contribution

It reveals a novel link between ferroelectricity and Berry curvature in tin telluride monolayers, enabling charge- and spin-controllable photocurrents for optoelectronic applications.

Findings

Ferroelectricity induces a significant Berry curvature dipole in tin telluride monolayers.

Manipulating polarization and photon handedness controls photocurrent direction and magnitude.

Berry curvature effects are comparable to those in small-gap topological materials.

Abstract

In symmetry-broken crystalline solids, pole structures of Berry curvature (BC) can emerge, and they have been utilized as a versatile tool for controlling transport properties. For example, the monopole component of the BC is induced by the time-reversal symmetry breaking, and the BC dipole arises from a lack of inversion symmetry, leading to the anomalous Hall and nonlinear Hall effects, respectively. Based on first-principles calculations, we show that the ferroelectricity in a tin telluride monolayer produces a unique BC distribution, which offers charge- and spin-controllable photocurrents. Even with the sizable band gap, the ferroelectrically driven BC dipole is comparable to those of small-gap topological materials. By manipulating the photon handedness and the ferroelectric polarization, charge and spin circular photogalvanic currents are generated in a controllable manner. The ferroelectricity in group-IV monochalcogenide monolayers can be a useful tool to control the BC dipole and the nonlinear optoelectronic responses.