Al_xGa_(1-x)N/GaN异质结构中2DEG的塞曼自旋分裂  

Zeeman Spin Splitting of 2DEG in Al_xGa_(1-x)N/GaN Heterostructures

作　　者：唐宁[1] 沈波[1] 韩奎[1] 卢芳超[1] 许福军[1] 秦志新[1] 张国义[1] 

机构地区：[1]北京大学人工微结构和介观物理国家重点实验室,北京100871

出　　处：《半导体技术》2008年第S1期147-149,共3页Semiconductor Technology

基　　金：国家"973"重点基础研究项目(2006CB604908;2006CB921607);国家自然科学基金(60806042;10774001;60736033;60628402);教育部博士点基金(200800011021;20060001018);北京市自然科学基金(4062017)

摘　　要：通过在低温和强磁场下的磁输运测量研究了非故意掺杂Al0.24Ga0.76N/GaN异质结构中二维电子气(2DEG)的磁电阻振荡现象。在强磁场下观察到了表征2DEG塞曼自旋分裂的舒勃尼科夫-德哈斯(SdH)振荡的分裂峰。通过分析SdH分裂峰的位置,获得了塞曼自旋分裂能量和g*的大小,发现由于交换相互作用,g*比g0有了显著的增加,同时g*随着磁场的增大而增大,说明随着磁场的增大,电子与电子的交换相互作用增强。Magnetoresistance oscillations of the two-dimensional electron gas(2DEG)in unintentionally doped Al0.24Ga0.76N/GaN heterostructures have been investigated by means of magnetotransport measurements at low temperatures and high magnetic fields.The spin-split peaks of the Shubnikov-de Haas(SdH)oscillations are observed at high magnetic fields,which are attributed to the Zeeman spin splitting of the 2DEG.The spin splitting energy and g are obtained by measuring the positions of the pairs of spin-split SdH maxima.It is found that g is enhanced over its bulk value in GaN due to the exchange interactions.Moreover,the g increase with an increase in magnetic field,indicating that many-body electron-electron interactions become stronger as the magnetic field increases.

关 键 词：AlxGa1-xN/GaN异质结构 二维电子气 自旋 

分 类 号：TN304.23[电子电信—物理电子学]