Ratchet transport of a two-dimensional electron gas at cyclotron resonance

TL;DR

This paper develops a microscopic theory explaining how quantum wells generate a direct current under alternating electric fields, with resonant enhancements at cyclotron and subharmonic resonances, influenced by magnetic field orientation.

Contribution

It introduces a detailed quantum ratchet model for quantum wells under magnetic fields, highlighting resonance effects and the impact of field polarization and tilt.

Findings

Ratchet current is enhanced at cyclotron resonance.

Additional resonance occurs at the subharmonic of cyclotron resonance.

Magnetic field tilt introduces new resonance features.

Abstract

The driving of charge carriers confined in a quantum well lacking the center of space inversion by an alternating electric field leads to the formation of a direct electric current. We develop a microscopic theory of such a quantum ratchet effect for quantum wells subjected to a static magnetic field. We show that the ratchet current emerges for a linearly polarized alternating electric field as well as a rotating electric field and drastically increases at the cyclotron resonance conditions. For the magnetic field tilted with respect to the quantum well normal, the ratchet current contains an additional resonance at the first subharmonic of the cyclotron resonance.