Analytic and geometric properties of photoinduced effects in noncentrosymmetric crystals: photovoltaic current and optical rectification

TL;DR

This paper introduces a new dispersion relation linking nonlinear optical responses in noncentrosymmetric crystals, revealing their connection to Berry phase theory and geometric potentials, aiding understanding of light-induced charge transport.

Contribution

It presents a novel dispersion relation connecting optical responses and demonstrates their relation to Berry phase and geometric potentials in noncentrosymmetric crystals.

Findings

Derived a dispersion relation between current and polarisation responses.

Linked the origin of photoinduced effects to Berry phase and geometric potentials.

Showed gauge invariance of the optical response expressions.

Abstract

An original dispersion relation between the stationary coherent nonlinear optical responses by current and polarisation is obtained. The dispersion relation provides a new complimentary tool that can be employed to study light-induced charge transport models and facilitate experimental data analysis. It is shown that the origin of the coherent current and the dc-polarisation induced in a noncentrosymmetric crystal under illumination is related to the theory of the Berry phase and can be represented in terms of the renormalised geometric potentials. This renormalisation originates from the extra phase difference acquired by a carrier in the light field on the quantum transition between the electronic bands. The gauge invariance of the corresponding expressions for the current and the polarisation is demonstrated.