Nonlinear theory of fractional microwave-induced magnetoresistance oscillations in a dc-driven two-dimensional electron system

TL;DR

This paper develops a nonlinear theoretical model for microwave-induced magnetoresistance oscillations in a dc-driven two-dimensional electron system, explaining experimental observations of frequency doubling and tripling near cyclotron resonance subharmonics.

Contribution

It introduces a multi-photon-assisted transport scheme controlled by current to explain nonlinear magnetoresistance oscillations and their frequency changes near cyclotron resonance subharmonics.

Findings

Frequency doubling of resistivity oscillations near the 2nd subharmonic

Frequency tripling near the 3rd subharmonic

Agreement with recent experimental results

Abstract

Microwave-induced nonlinear magnetoresistance in a dc-driven two-dimensional electron system is examined using a multi-photon-assisted transport scheme direct controlled by the current. It is shown that near the 2nd subharmonic of the cyclotron resonance, the frequency of the resistivity oscillation with the magnetic-field-normalized current-density is double that at the cyclotron resonance and its harmonics, in excellent agreement with recent experimental findings by Hatke {\it et al.} [Phys. Rev. Lett. {\bf 101}, 246811 (2008)]. The current-induced alternative emergence of resonant two-photon and single-photon processes is responsible for this frequency doubling. Near the third subharmonic of the cyclotron resonance, the current-induced consecutive appearance of resonant 0-/3-photon, two-photon, and single-photon processes may lead to the frequency tripling of the resistivity oscillation.