Spin Splitting in modulation-doped AlGaN/GaNtwo-dimensional electron gas

摘要

AlGaN/GaN heterostructure devices have recently been attracting muchattention because of their potential for high-performance microwave applications. Therefore,the electronic properties of a two-dimensional electron gas (2DEG) in AlGaN/GaNheterostructures have recently been discussed. We studied the magnetoresistance oscillation ofthe 2DEG at 0.4 K for various back-gate voltages, and observed multiple oscillations resultingfrom spin splitting. The magnetoresistance shows clear beating due to the superposition ofthree oscillations. The frequency interval between the first and second largest frequenciesis proportional to the total electron concentration and the measured spin-orbit interactionparameter agrees with the theoretical one. Therefore, the first and second largest frequenciesare found to correspond to spin splitting caused by the spin-orbit interaction.