【作者】 唐宁； 沈波； 韩奎； 卢芳超； 许福军； 秦志新； 张国义；

【Author】 Tang Ning,Shen Bo,Han Kui,Lu Fangchao,Xu Fujun,Qin Zhixin,Zhang Guoyi (State Key Laboratory for Artificial Microstructure and Mesoscopic Physics,Peking University,Beijing 100871,China)

【机构】 北京大学人工微结构和介观物理国家重点实验室；

【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Al_0.24Ga_0.76N/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。更多还原

【Abstract】 Magnetoresistance oscillations of the two-dimensional electron gas（2DEG） in unintentionally doped Al_0.24Ga_0.76N/GaN heterostructures have been investigated by means of magneto-transport 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.更多还原