Parabolic negative magnetoresistance in p-Ge/Ge1-xSix heterostructures

TL;DR

This study investigates quantum corrections to conductivity in high-mobility p-Ge/Ge1-xSix heterostructures, revealing negative magnetoresistance behavior due to weak localization and electron-electron interactions at low temperatures and moderate magnetic fields.

Contribution

It provides experimental analysis of quantum corrections in p-Ge/Ge1-xSix heterostructures, estimating the interaction constant and separating contributions of weak localization and electron-electron interactions.

Findings

Negative magnetoresistance observed with logarithmic temperature dependence.

Linear dependence of magnetoresistance on B^2 for B >= 0.1T.

Estimated Hartree interaction constant F_/sigma = 0.44.

Abstract

Quantum corrections to the conductivity due to the weak localization (WL) and the disorder-modified electron-electron interaction (EEI) are investigated for the high-mobility multilayer p-Ge/Ge1-xSix heterostructures at T = (0.1 - 20.0)K in magnetic field B up to 1.5T. Negative magnetoresistance with logarithmic dependence on T and linear in B^2 is observed for B >= 0.1T. Such a behavior is attributed to the interplay of the classical cyclotron motion and the EEI effect. The Hartree part of the interaction constant is estimated (F_/sigma = 0.44) and the WL and EEI contributions to the total quantum correction /Delta /sigma at B = 0 are separated (/Delta /sigma_{WL} ~ 0.3/Delta /sigma; /Delta /sigma_{EEI} ~ 0.7/Delta /sigma).