Abstract

The dynamics of electronic states under the action of a periodic electric field applied to a quantum dot created by magnetic barriers at the one-dimensional edge of a two-dimensional topological insulator based on a HgTe/CdTe quantum well has been studied. A configuration with two discrete levels is considered and transitions to continuum states above barriers are taken into account. The frequency of oscillations of the discrete level populations has been calculated for various field amplitudes. It has been shown numerically and analytically that the inclusion of the continuous spectrum leads to a decrease in the total population of discrete levels in time. The characteristic times of this decrease corresponding to transitions to continuum have been determined. The dynamics of average values of the energy, spin projections, coordinates, local probability density, and local spin density has been calculated. Time-averaged local probability density current that describes the quantum dot escape at transitions to the continuous spectrum has been calculated. The results of this work can be useful for the design of new generations of nanoelectronics and spintronics devices based on topological insulators.

中文翻译：

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包含连续体状态的拓扑绝缘体边缘的量子点中的自旋共振

摘要

研究了在基于HgTe / CdTe量子阱的二维拓扑绝缘体的一维边缘上由磁势垒产生的量子点施加的周期性电场作用下电子态的动力学。考虑具有两个离散级别的配置，并考虑到障碍之上的连续状态的转换。对于各种场振幅，已经计算出离散能级总体的振荡频率。数值和分析表明，连续光谱的包含导致时间上离散水平总数的减少。已经确定了这种减少对应于过渡到连续体的特征时间。能量平均值，自旋投影，坐标，局部概率密度和局部自旋密度已被计算。已计算出描述量子点在过渡到连续光谱时逃逸的时间平均局部概率密度电流。这项工作的结果对于基于拓扑绝缘体的新一代纳米电子和自旋电子器件的设计可能是有用的。