Al_(0.22)Ga_(0.78)N/GaN二维电子气中的弱局域和反弱局域效应  

The weak antilocalization and localization phenomenon in AlGaN/GaN two-dimensional electron gas

作　　者：朱博[1] 桂永胜[2] 周文政[2] 商丽燕[2] 郭少令[2] 褚君浩[2] 吕捷[3] 唐宁[3] 沈波[3] 张福甲[1] 

机构地区：[1]兰州大学物理系,兰州730000 [2]中国科学院上海技术物理研究所红外物理国家重点实验室,上海200083 [3]北京大学物理学院人工微结构和介观物理国家重点实验,北京100871

出　　处：《物理学报》2006年第5期2498-2503,共6页Acta Physica Sinica

基　　金：国家重点基础研究发展规划(批准号:2001GB309506);国家自然科学基金(批准号:60221502;10374094;60444007;60136020);国家杰出青年基金(批准号:60325413);教育部博士点基金(批准号:20020284023)资助的课题~~

摘　　要：通过磁输运测量研究了Al0·22Ga0·78N/GaN二维电子气的电子相干散射中的弱局域和反弱局域化现象.在外加弱磁场的情况下,该系统表现出正-负磁阻的变化,说明在Al0·22Ga0·78N/GaN异质结中存在晶体场引起的电子自旋-轨道散射.同时讨论了二维电子气中不同的散射时间对温度的依赖关系,实验得到的非弹性散射时间与温度成反比,表明非弹性散射机理主要来源于小能量转移的电子-电子散射.The weak localization and weak antilocalization effects in the coherent scattering of two dimensional electron gas（2DEG） have been observed in Al0.22 Ga0.78 N/GaN heterostructures by the magneto-transport measurement. The change of magnetoresistance from positive to negative under a perpendicular low magnetic field indicates that electron spin-orbit scattering caused by crystal field exists in Al0.22 Ga0.78 N/GaN heterojunction. The relation between the spin-orbit scattering time and the temperature is discussed for 2DEG, the inelastic scattering time measured by experiment shows a strong temperature dependence according to T^- 1 rule, which indicates that the electron-electron scattering with small energy transfer is the dominant inelastic process.

关 键 词：二维电子气 弱局域 磁阻 

分 类 号：O737[理学—晶体学]