Far-infrared induced current in a ballistic channel -- potential barrier structure

TL;DR

This paper investigates electron transport in a ballistic multi-mode channel under far-infrared radiation, revealing resonant photocurrent peaks due to Rabi oscillations and proposing a method to reconstruct mode spectra via gate tuning.

Contribution

It introduces a novel approach to analyze mode spectra in ballistic channels using FIR-induced photocurrent peaks without requiring a tunable FIR source.

Findings

Resonant peaks in photocurrent occur at frequencies matching mode energy separation.

Rabi oscillations cause distinct photocurrent peaks in the channel.

Proposed method allows spectrum reconstruction by gate voltage variation.

Abstract

We consider electron transport in a ballistic multi-mode channel structure in the presence of a transversely polarized far-infrared (FIR) field. The channel structure consists of a long resonance region connected to an adiabatic widening with a potential barrier at the end. At frequencies that match the mode energy separation in the resonance region we find distinct peaks in the photocurrent, caused by Rabi oscillations in the mode population. For an experimental situation in which the width of the channel is tunable via gates, we propose a method for reconstructing the spectrum of propagating modes, without having to use a tunable FIR source. With this method the change in the spectrum as the gate voltage is varied can be monitored.