Weak antilocalization and beating pattern in high electron mobility Al _xGa_1-xN/GaN two-dimensional electron gas with strong Rashba spin-orbit coupling

The weak antilocalization (WAL) effects of the two-dimensional electron gas (2DEG) in high mobility Al_xGa_1-xN/GaN heterostructure as well as beating patterns in the Shubnikov-de Haas (SdH) oscillatory magnetoresistance have been investigated by means of magnetotransport measurements before and after illumination. The zero-field spin splitting mainly arising from the Rashba spin-orbit coupling effect is studied using the weak antilocalization and beating patterns analysis, respectively. The Rashba spin-orbit coupling constant α deduced using the weak antilocalization analysis showed a good agreement with that estimated from the analysis of the beating patterns for the sample before and after illumination. For our sample, the electron motion in the high mobility system is in the ballistic regime, the experimental WAL curves were fitted by a simulated quantum conductance correction according to a model proposed by [Golub [Phys. Rev. B 71, 235310 (2005)].