High-quality quantum point contacts in GaN∕AlGaN heterostructures

Abstract

We study the transport properties of quantum point contacts in a GaN∕AlGaN heterostructure. The conductance of our devices shows well-quantized plateaus, which spin-split in high perpendicular magnetic field. The g factor is 2.55, as derived from the point contact subband splitting versus perpendicular magnetic field. In addition to the well-resolved plateaus, we also observe evidence of “0.7 structure” which has been mainly investigated in the GaAs system.