Direct current driven by ac electric field in quantum wells

TL;DR

This paper demonstrates that ac electric fields can induce a direct current in quantum wells with structural asymmetry, depending on polarization, frequency, and magnetic fields, supported by a microscopic model and analytical theory.

Contribution

It introduces a new theoretical framework explaining how ac electric fields generate dc currents in asymmetric quantum wells, considering polarization and magnetic effects.

Findings

dc current depends on ac field polarization and frequency

both linear and circular polarizations can induce current

magnetic fields influence the current generation

Abstract

It is shown that the excitation of charge carriers by ac electric field with zero average driving leads to a direct electric current in quantum well structures. The current emerges for both linear and circular polarization of the ac electric field and depends on the field polarization and frequency. We present a micoscopic model and an analytical theory of such a nonlinear electron transport in quantum wells with structure inversion asymmetry. In such systems, dc current is induced by ac electric field which has both the in-plane and out-of-plane components. The ac field polarized in the interface plane gives rise to a direct current if the quantum well is subjected to an in-plane static magnetic field.