Al_xGa_(1-x)N/GaN异质结构中二维电子气的自旋性质

Ⅲ族氮化物材料有很长的电子自旋弛豫时间以及很高的居里温度,成为近年来半导体自旋电子学研究的重要材料体系之一。介绍了目前两种最主要的研究AlxGa1-xN/GaN异质结构中二维电子气(2DEG)自旋性质的物理效应:磁电阻的舒伯尼科夫-德哈斯拍频振荡和弱反局域效应,回顾了AlxGa1-xN/GaN异质结构中2DEG自旋性质的研究进展。AlxGa1-xN/GaN异质结构材料中有很强的极化电场,诱导产生很高浓度的2DEG,能够产生相当大能量的自旋分裂,并且这种自旋分裂可以被栅压所调控,因此在自旋场效应晶体管方面有很好的应用前景。然而要实现GaN基自旋电子学器件的应用,GaN中自旋注入效率是目前所面临的问题。

Spin Properties of the Two-Dimensional Electron Gas in Al_xGa_(1-x)N/GaN Heterostructures

Owing to the advantages of long spin relaxation time and high Curie temperature,Ⅲ-nitride semiconductor material is one of the most favorite materials in developing spintronic devices.Two main physical effects are introduced to study spin properties of the two-dimensional electron gas in Al_xGa_(1-x)N/GaN heterostructures,including beating pattern Shubnikov-de Haas oscillations and weak-antilocalization effect.The development of the spin properties of the 2DEG in Al_xGa_(1-x)N/GaN heterostructures is reviewed.Due to the large polarization-induced field in Al_xGa_(1-x)N/GaN heterostructures,a 2DEG with large sheet carrier concentration can be obtained.The spin splitting energy of the 2DEG is very large in Al_xGa_(1-x)N/GaN heterostructures.The spin splitting can also be controlled by the gate voltage.Thus it has good application prospects in spin field effect transistors.However,the spin injection efficiency in GaN is still a major problem which hinders the devolopment of GaN-based spintronic devices.