Switching of the Dyakonov-Perel spin relaxation owing to the Rashba spin-orbit interaction (SOI) is theoretically studied in a semiconductor heterostructure with three quantum wells. The action of the present spin-relaxation switching is based on the gate-voltage induced electron transfer from the central well with vanishing Rashba SOI to the left or right well with large Rashba SOI. The spin-relaxation rate is calculated by extending the Dyakonov-Perel theory of the spin relaxation in a single subband to that in more than one subband in order to take into account the contribution from electrons in excited subbands at higher temperatures. It is shown that the on:off ratio of the spin-relaxation rate at room temperature reaches ${10}^6$ by choosing widths and compositions of well and barrier layers so as to reduce electron population in excited subbands, which gives an undesirable spin relaxation. The present spin-relaxation switching is expected to improve the on:off ratio of the current in the spin-lifetime field effect transistor.

中文翻译：

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栅极电压引起的三量子阱结构中自旋弛豫率的开关

理论上在具有三个量子阱的半导体异质结构中研究了由于Rashba自旋轨道相互作用（SOI）而引起的Dyakonov-Perel自旋弛豫的转换。当前的自旋松弛开关的作用是基于栅极电压感应的电子从具有消失的Rashba SOI的中心阱向具有较大的Rashba SOI的左阱或右阱转移的。通过将单个子带中的自旋弛豫的Dyakonov-Perel理论扩展到一个以上子带中的Dyakonov-Perel理论来计算自旋弛豫速率，以便考虑到较高温度下受激子带中电子的贡献。结果表明，室温下自旋松弛速率的开/关比达到${10}^6$通过选择阱和势垒层的宽度和组成，以减少受激子带中的电子数量，这会带来不良的自旋弛豫。目前的自旋松弛开关有望改善自旋寿命场效应晶体管中电流的通断比。