arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1407.0182cond-mat.mes-hall
收藏

低对称量子阱中的弱局域化

Weak localization in low-symmetry quantum wells

F. V. Porubaev, L. E. Golub

摘要:

发展了沿[110]和[111]晶轴生长的半导体量子阱中电子的弱局域化理论。计算了对称掺杂量子阱中弱局域化引起的反常电导修正。该理论适用于整个经典弱磁场范围内的弱局域化的弹道和扩散区域。我们表明,在体反转不对称的存在下,磁阻是负的:线性的电子动量自旋轨道相互作用对电导率没有影响,而立方的动量耦合抑制弱本地化没有改变的校正符号。在对称掺杂量子阱中掺杂层中杂质的随机位置产生电场,这导致位置相关的Rashba耦合。这种随机的自旋-轨道相互作用导致自旋弛豫,这改变了异常磁导率的符号。所得到的表达式允许从输运测量确定(110)和(111)量子阱中的电子自旋弛豫时间。

英文摘要:

Theory of weak localization is developed for electrons in semiconductor quantum wells grown along [110] and [111] crystallographic axes. Anomalous conductivity correction caused by weak localization is calculated for symmetrically doped quantum wells. The theory is valid for both ballistic and diffusion regimes of weak localization in the whole range of classically weak magnetic fields. We demonstrate that in the presence of bulk inversion asymmetry the magnetoresistance is negative: The linear in the electron momentum spin-orbit interaction has no effect on the conductivity while the cubic in momentum coupling suppresses weak localization without a change of the correction sign. Random positions of impurities in the doping layers in symmetrically doped quantum wells produce electric fields which result in position-dependent Rashba coupling. This random spin-orbit interaction leads to spin relaxation which changes the sign of the anomalous magnetoconductivity. The obtained expressions allow determination of electron spin relaxation times in (110) and (111) quantum wells from transport measurements.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑