Photovoltaic effect in a gated two-dimensional electron gas in magnetic field

TL;DR

This paper theoretically investigates the photovoltaic effect in a gated two-dimensional electron gas under magnetic field, highlighting oscillations and resonance effects influenced by terahertz radiation and plasma wave damping.

Contribution

It introduces a theoretical model explaining the photovoltaic response oscillations and resonance enhancements in a gated 2D electron gas subjected to magnetic fields.

Findings

Photovoltage oscillates with magnetic field near Shubnikov-de Haas oscillations.

Maximum photovoltage occurs at cyclotron resonance.

Oscillating mobility dependence causes non-linear photoresponse.

Abstract

The photovoltaic effect induced by terahertz radiation in a gated two-dimensional electron gas in magnetic field is considered theoretically. It is assumed that the incoming radiation creates an ac voltage between the source and gate and that the gate length is long compared to the damping length of plasma waves. In the presence of pronounced Shubnikov-de Haas oscillations, an important source of non-linearity is the oscillating dependence of the mobility on the ac gate voltage. This results in a photoresponse oscillating as a function of magnetic field, which is enhanced in the vicinity of the cyclotron resonance, in accordance with recent experiments. Another, smooth component of the photovoltage, unrelated to SdH oscillations, has a maximum at cyclotron resonance.