# Photovoltaic Effect from the Viewpoint of Time-reversal Symmetry

## TL;DR

This paper provides a theoretical analysis showing that breaking time-reversal symmetry is essential for inducing charge transport and photovoltaic effects under external fields, offering microscopic insights into these phenomena.

## Contribution

It introduces a theoretical framework linking time-reversal symmetry breaking to photovoltaic effects and optical current control, which is a novel perspective.

## Key findings

- Breaking of time-reversal symmetry is necessary for charge transport.
- Time-reversal symmetry breaking enables photovoltaic effects.
- Provides microscopic understanding of optical current control.

## Abstract

We theoretically investigate field-induced charge-transport processes from the viewpoint of time-reversal symmetry. We analytically demonstrate that breaking of the time-reversal symmetry is a necessary condition to induce charge-transport and direct-current by external fields. This finding provides microscopic insights into photovoltaic effects and optical-control of currents.