Effect of Zeeman splitting on magnetoresistivity of 2D hole gas in a Ge_{1-x}Si_x/Ge/Ge_{1-x}Si_x quantum well

TL;DR

This study investigates how Zeeman splitting influences the magnetoresistivity in a 2D hole gas within Ge/SiGe quantum wells, revealing a transition from metallic to insulating behavior under magnetic fields and temperature scaling of positive magnetoresistance.

Contribution

It demonstrates the impact of Zeeman splitting on electron-electron interactions and resistivity behavior in 2D hole systems with highly anisotropic g-factors.

Findings

Observed transition from metallic to insulator behavior with magnetic field.

Magnetoresistance scales with B/T.

Zeeman splitting suppresses triplet electron-electron interactions.

Abstract

For a two-dimensional (2D) hole system (confined within Ge layers of a multilayered p-Ge/Ge_{1-x}Si_x heterostructure) described by Luttinger Hamiltonian with the g-factor highly anisotropic for orientations of magnetic field perpendicular and parallel to the 2D plane (g_perp >> g_par), reported is an observation of low-temperature transition from metallic (dR/dT > 0) to insulator (dR/dT < 0) behavior of resistivity R(T) induced by a perpendicular magnetic field B. The revealed positive magnetoresistance scales as a function of B/T. We attribute this finding to a suppression of the triplet channel of electron-electron (hole-hole) interaction due to Zeeman splitting in the hole spectrum.