Directional Photocurrent Generated by Quantum Interference Control

TL;DR

This paper demonstrates that quantum interference between multi-photon absorption processes in semiconductors can generate a directional photocurrent, producing a narrow electron beam without an external electric field.

Contribution

It introduces a novel mechanism where interference between two-photon and three-photon absorption creates a highly directional photocurrent in semiconductors.

Findings

Interference between two-photon and three-photon absorption produces a narrow electron beam.

The generated photocurrent has a specific directional bias.

This mechanism enables control of electron flow without external fields.

Abstract

Although the absorption of light in a bulk homogeneous semiconductor produces photocarriers with non-zero momentum, it generally does not produce a current in the absence of an applied electric field because equal amounts of carriers with opposite momentum are injected. The interference of absorption processes, for example, between one-photon and two-photon absorption, can produce a current because constructive interference for carriers with one momentum can correspond to destructive interference for carriers with the opposite momentum. We show that for the interference between two-photon and three-photon absorption, the current has a narrower angular spread, i.e., a ``beam'' of electrons in a specified direction is produced in the semiconductor.