【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 .2 2 Ga0 .78N/GaN异质结二维电子气 ( 2DEG)的磁电阻振荡现象。观察到了磁致子带间散射 (MIS)效应。在极低温下观察到了表征两个子带被 2DEG占据的双周期舒勃尼科夫 德哈斯 (SdH)振荡。实验观察到MIS效应引起的磁电阻振荡的幅度随温度上升略有减小 ,振荡的频率为两个子带SdH振荡频率之差。随着温度的升高 ,MIS振荡成为主要的振荡。由于SdH振荡和MIS振荡对温度的依赖关系不同 ,实验观察到SdH和MIS振荡之间的调制在温度 10和 17K之间最为强烈 ,其它温度下的调制很弱。更多还原

【Abstract】 Magnetoresistance oscillations of the two-dimensional electron gas （2DEG） in unintentionally doped Al_0.22Ga_0.78N/GaN heterostructures were investigated by means of magnetotransport measurements at low temperatures and high magnetic fields. Double periodic Shubnikov-de Haas （SdH） oscillations were observed at very low temperatures, which indicates two subbands are occupied by the 2DEG in the triangular quantum well at the heterointerface. Magnetointersubband scattering （MIS） oscillations become dominant with increasing temperature. It is found that the MIS oscillations become slightly weaker with increasing temperature. Due to the different temperature dependence between the SdH and the MIS oscillations, it is observed that the SdH oscillations modulated strongly by the MIS oscillations between 10 and 17 K while the modulations are very weak at other temperatures.更多还原