This is a theoretical study of the reversal of a localized quantum spin induced by sequential injection of spins for a spin quantum dot that has a quantum spin. The system consists of ``electrode/quantum well(QW)/dot/QW/electrode" junctions, in which the left QW has an energy level of conduction electrons with only up-spin. We consider a situation in which up-spin electrons are sequentially injected from the left electrode into the dot through the QW and an exchange interaction acts between the electrons and the localized spin. To describe the sequentially injected electrons, we propose a simple method based on approximate solutions from the time-dependent Schr$\ddot{\rm o}$dinger equation. Using this method, it is shown that the spin reversal occurs when the right QW has energy levels of conduction electrons with only down-spin. In particular, the expression of the reversal time of a localized spin is derived and the upper and lower limits of the time are clearly expressed. This expression is expected to be useful for a rough estimation of the minimum relaxation time of the localized spin to achieve the reversal. We also obtain analytic expressions for the expectation value of the localized spin and the electrical current as a function of time. In addition, we found that a system with the non-magnetic right QW exhibits spin reversal or non-reversal depending on the exchange interaction.
Direct demonstration of time-reversal-symmetry-breaking spin injection from a compensated magnet
CIC nanoGUNE BRTA（nanoGUNE BRTA 研究中心）；University of the Basque Country (UPV/EHU)（巴斯克大学）；Institute of Physics, Czech Academy of Sciences（捷克科学院物理研究所）；Charles University（查理大学）；TUD University of Technology Dresden（德累斯顿工业大学）；Universidad del Norte（北方大学）；Johannes Gutenberg Universität Mainz（美因茨约翰内斯古腾堡大学）；UdelaR（乌拉圭共和国大学）；University of Jyvaskyla（耶瓦斯基莱大学）；Aix-Marseille Univ.（艾克斯-马赛大学）
Spin-galvanic response to non-equilibrium spin injection in superconductors with spin-orbit coupling
Universidad del País Vasco（巴斯克大学）；IKERBASQUE, Basque Foundation for Science（伊克拉巴斯基奎，巴斯克科学基金会）；Donostia International Physics Center (DIPC)（圣塞巴斯蒂安国际物理中心）；Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU（材料物理中心（CFM-MPC），CSIC-UPV/EHU联合中心）
Reducing critical current for spin-transfer-torque-induced magnetization reversal in CPP-GMR devices: effect of low damping and enhanced spin scattering asymmetry in $Co_2FeGa_{0.5}Ge_{0.5}$ Heusler alloy
Vortex-mediated spin current injection into two-dimensional superconductor NbSe2
Southern University of Science and Technology（南方科技大学）；Quantum Science Center of Guangdong–Hong Kong–Macao Greater Bay Area (Guangdong)（粤港澳大湾区量子科学中心）；Guangdong Provincial Key Laboratory of Advanced Thermoelectric Materials and Device Physics（广东省先进热电材料与器件物理重点实验室）
Dynamical Stabilization of Inverted Magnetization and Antimagnons by Spin Injection in an Extended Magnetic System
ETH Zurich（苏黎世联邦理工学院）；Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg（斯特拉斯堡大学，法国国家科学研究中心，斯特拉斯堡材料物理与化学研究所）；Université Grenoble Alpes, CNRS, Institut Néel（格勒诺布尔阿尔卑斯大学，法国国家科学研究中心，尼尔研究所）；University of Konstanz（康斯坦茨大学）
