Nonlinear characteristics of T-branch junctions: Transition from ballistic to diffusive regime

Abstract

Nonlinear electrical characteristics of nanostructured T-branch junctions (TBJs) made of two-dimensional electron gas in an InGaAs∕InAlAs heterostructure were studied by a systematic variation of both the device size and the operating temperature. We have found that two distinct mechanisms are responsible for the electronic transport in TBJs and their resulting nonlinear characteristics, namely, the nonlinear ballistic effect at low applied voltages and the intervalley transfer at high voltages. Detailed experimental analysis for each mechanism and their contributions with respect to the TBJ’s nanochannel length and operating temperature are discussed.