Correlation Field Analysis of Magnetoresistance of GaN/AlGaN Heterostructure Grown on Si Substrate

Abstract

We analyze the conductance fluctuations for a bulk two-dimensional electron system in a GaN/Al 0:15 Ga 0:85 N heterostructure grown on a p-type Si(111) substrate, and calculate the correlation field B c with the autocorrelation function FðÁBÞ ¼ hGðB þ ÁBÞ À GðBÞi, in the temperature range 0:27 T 3 K, which is employed as a self-thermometer to obtain the effective carrier temperature T e as a function of the measurement current I. We find that the temperature dependence agrees well with simple expectations for universal conductance fluctuations in metals, while the observed amplitude is reduced. In the study of hot-carrier phenomena, we also obtain T e $ I 0:5 , which agrees with some theoretical prediction.