Siδ掺杂GaAs多量子阱的磁量子输运

QUANTUM MAGNETOTRANSPORT OF Siδ-DOPING GaAs MULTIPLE QUANTUM WELL

使用ＭＢＥ技术低温生长了含有３个Ｓｉδ掺杂层的ＧａＡｓ外延片，形成三量子阶结构．在４．２～３００Ｋ温区０．１Ｔ的电磁铁上测量了样品载流子浓度和迁移率随温度的变化．在０．３～４．２Ｋ（３Ｈｅ温区）和０～７Ｔ强磁场下测量了样品的横向磁阻、纵向磁阻和霍尔电阻．观察到了横向磁阻的ＳｄＨ振荡和纵向磁阻的抗磁ＳｄＨ振荡．根据实验结果着重讨论了纵向磁阻振荡的起源以及霍尔振荡的含义，简单分析了δ掺杂二维电子气中磁致金属一绝缘体转变的实验条件．

By using the MBE technique, a GaAs film which contained three Si δ-doping layers was fabricated at low temperature, and triple QWs structure was formed. The transverse magnetoresistance, longitudinal magnetoresistallce and Hail resistance were measured from 0.3K to 4.2K at high magnetic field up to 7 T. The SdH oscillatinn of the transverse magnetoresistance and the 'diamaglletic' SdH oscillation of the longitudinal magnetoresistance were observed. Based on the experimental results, the mechanisms of the longitudinal oscillation and the Hall oscillation are discussed. The possibility of the magnetic-induced metal-insulator transition is briefly analyzed.