The goal of this work is to show how the thermospin polarization current in a quantum ring changes in the presence of Rashba spin-orbit coupling and a quantized single photon mode of a cavity the ring is placed in. Employing the reduced density operator and a general master equation formalism, we find that both the Rashba interaction and the photon field can significantly modulate the spin polarization and the thermospin polarization current. Tuning the Rashba coupling constant, degenerate energy levels are formed corresponding to the Aharonov-Casher destructive phase interference in the quantum ring system. Our analysis indicates that the maximum spin polarization can be observed at the points of degenerate energy levels due to spin accumulation in the system without the photon field. The thermospin current is thus suppressed. In the presence of the cavity, the photon field leads to an additional kinetic momentum of the electron. As a result the spin polarization can be enhanced by the photon field.
Twist- and gate-tunable proximity spin-orbit coupling, spin relaxation anisotropy, and charge-to-spin conversion in heterostructures of graphene and transition-metal dichalcogenides
Manipulation of the Land$\acute{\text{e}}$ g-factor in InAs quantum dots through the application of anisotropic gate potentials: Exact diagonalization, numerical and perturbation methods
为了实现固态量子计算,我们研究了InAs量子点中各向异性栅势和磁场引起的电子自旋的Land $\acute{\text{e}}$ g因子的变化.在本文中,我们提出了解析表达式和数值模拟的土地$\acute{\text{e}}$ g因子的变化,各向同性和各向异性量子点。使用这两种分析技术和数值模拟,我们表明,Rashba自旋-轨道耦合的g-因子的变化与电场的制度,其中发生水平交叉或anticrossing有重大贡献。特别是,电场的可调性示出通过强Rashba自旋轨道相互作用,以涵盖广泛的g因子。本文的另一个主要结果是,各向异性的门势在轨道角动量中产生猝灭效应,如果对称和非对称量子点的面积保持恒定,则该效应减小了g因子的E场和B场可调谐性的变化。我们确定的土地$\acute{\text{e}}$ g-因子的变化中的电子态的水平交叉和反交叉。我们模拟了电子自旋的波函数,并估计了自旋态$|0,-1,+1/2>$和$|0,0,-1/2>$对应于最近实验研究的量子点的反交叉的大小(Phys. Rev. Lett. \textbf{104},246801(2010))。
Optical manipulation of Rashba-split 2-Dimensional Electron Gas
在自旋电子器件中,主动控制电子自旋自由度的两种主要方法涉及静磁场或电场。另一种途径依赖于光场的应用来产生自旋电流,这有望提高自旋器件的性能,从而实现更快、更有效的自旋逻辑。迄今为止,研究主要集中在通过光电流效应的自旋电流的光学注入,而对本征自旋分裂的直接光学控制知之甚少。在这里,为了探索材料自旋特性的全光学操纵,我们考虑了半导体界面处的Rashba效应。由于其优越的可调谐性,拉什巴效应长期以来一直是自旋电子学领域的主要内容,这允许观察完全自旋相关的现象,例如半导体器件中的自旋-霍尔效应、自旋-电荷转换和自旋扭矩。在这项工作中,通过时间和角度分辨光电子能谱(TR-ARPES),我们证明了超快的光激发可以用来操纵的Rashba诱导的自旋分裂的二维电子气(2DEG)的拓扑绝缘体Bi $_{2}$ Se $_{3}$的表面工程。我们建立了光致光电压和载流子再分布-这在协调一致地调制亚皮秒时间尺度上的自旋轨道耦合强度-可以提供一个前所未有的平台,实现所有光驱动的太赫兹自旋逻辑器件。
Weak localization as probe of spin-orbit-induced spin-split bands in bilayer graphene proximity coupled to WSe$_2$
RWTH Aachen University(亚琛工业大学);Forschungszentrum Jülich(于利希研究中心);Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST(加泰罗尼亚纳米科学与技术研究所(ICN2,西班牙高等科研理事会与巴塞罗那自治大学联合));National Institute for Materials Science(国立材料研究所)