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arXiv 1509.03479cond-mat.mes-hall
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Mn掺杂体半导体自旋转移动力学的量子动力学理论与非零Mn磁化强度的Markov极限的比较

Comparison between a quantum kinetic theory of spin transfer dynamics in Mn doped bulk semiconductors and its Markov limit for non-zero Mn magnetization

Moritz Cygorek, Vollrath Martin Axt

摘要:

利用微观量子动力学理论研究了Mn掺杂半导体中由于s-d-交换相互作用引起的载流子与Mn自旋之间的转移。我们表明,自旋转移动力学是定性不同的载流子自旋平行和垂直于Mn磁化的组件。从量子动力学方程出发,我们导出了相应的马尔可夫极限,它与基于费米黄金法则的速率方程等价。由此产生的方程类似于广泛使用的朗道-利夫希茨-吉尔伯特方程,但也描述了真正的自旋转移由于量子校正。虽然它是已知的马尔可夫速率描述工作良好的散装系统时,初始锰磁化为零,我们发现大的定性偏差从全量子动力学理论有限的初始锰磁化。这些偏差主要反映了相互作用中高于主导阶的修正,而这在黄金法则型速率中没有考虑。

英文摘要:

We investigate the transfer between carrier and Mn spins due to the s-d-exchange interaction in a Mn doped bulk semiconductor within a microscopic quantum kinetic theory. We demonstrate that the spin transfer dynamics is qualitatively different for components of the carrier spin parallel and perpendicular to the Mn magnetization. From our quantum kinetic equations we have worked out the corresponding Markov limit which is equivalent to rate equations based on Fermi's golden rule. The resulting equations resemble the widely used Landau-Lifshitz-Gilbert-equations, but also describe genuine spin transfer due to quantum corrections. Although it is known that the Markovian rate description works well for bulk systems when the initial Mn magnetization is zero, we find large qualitative deviations from the full quantum kinetic theory for finite initial Mn magnetizations. These deviations mainly reflect corrections of higher than leading order in the interaction which are not accounted for in golden rule-type rates.

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。

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