摘要
为解释以往在GaAs/n型AlGaAs异质结中所观测到的负平行磁阻现象(NPMR),本文首次提出了一新物理模型。在平行界面的磁场中,二维电子的子能带色散关系沿平行界面的k_y波矢方向发生位移。这种横向位移抑制了粒子-粒子通道中扩散传播子的发散行为,导致了在平行磁场中由局域化效应诱导的负磁阻效应。本文的物理模型与B、Lin的实验数据符合良好,并且由拟合求得了正确的电子在界面势阱中的平均纵向限制长度〈z〉和位相损失时间z_(?)。
A new physical model has been developed to explain previously observed negative parallelmagnetoresistances (NPMR) in terms of suppression of the localization in disordered two dimensionalelectron systems by lateral shift of subband parabolas in a magnetice field parallelto the two dimensional (2D) plane.Excellent agreement has been achieved between the resultsobtained with our model and B. Lin's data, leading to obtain proper values for both averageconfining length <Z> and dephasing time
基金
国家自然科学基金
