Radiation-induced resistance oscillations in a 2D hole gas: a demonstration of a universal effect

TL;DR

This paper demonstrates that microwave-induced resistance oscillations and zero resistance states are universal phenomena in 2D hole gases, extending the understanding from electrons to holes in semiconductor quantum wells.

Contribution

It provides a universal analytical expression for magnetoresistance in 2D hole gases, explaining the phase shift and minima positions, and explores interference effects with multiple carrier types.

Findings

Radiation-induced resistance oscillations occur in 2D hole gases.

Zero resistance states are observed in p-type semiconductors.

Interference effects arise from different carrier effective masses.

Abstract

We report on a theoretical insight about the microwave-induced resistance oscillations and zero resistance states when dealing with p-type semiconductors and holes instead of electrons. We consider a high-mobility two-dimensional hole gas hosted in a pure Ge/SiGe quantum well. Similarly to electrons we obtain radiation-induce resistance oscillations and zero resistance states. We analytically deduce a universal expression for the irradiated magnetoresistance, explaining the origin of the minima positions and their $1/4$ cycle phase shift. The outcome is that these phenomena are universal and only depend on radiation and cyclotron frequencies. We also study the possibility of having simultaneously two different carriers driven by radiation: light and heavy holes. As a result the calculated magnetoresistance reveals an interference profile due to the different effective masses of the two types of carriers.