利用吸收边界条件研究与导电电子系统耦合的自旋弛豫动力学的超长时间尺度
Accessing long timescales in the relaxation dynamics of spins coupled to a conduction-electron system using absorbing boundary conditions
摘要：
计算了弱磁场作用下经典自旋与大电导电子系统相互作用的弛豫时间。我们跟踪自旋和导电电子动力学的时间尺度上，这超过了特征电子尺度，这是由逆最近邻跳跃超过五个数量级。这是实现了一种新的建设吸收边界条件，它采用了广义Lindblad主方程的方法耦合的边缘网站的传导电子紧束缚模型的外部浴。标准Lindblad方法吸收边界的失败可追溯到最初由于耦合到浴而产生的人工激励。这可以通过引入Lindblad参数矩阵并通过固定这些矩阵来完美地抑制初始状态伪影以及传播到系统边界的物理激励的反射来治愈。数值结果和讨论的电子结构的通用一维模型。
英文摘要：
The relaxation time of a classical spin interacting with a large conduction-electron system is computed for a weak magnetic field, which initially drives the spin out of equilibrium. We trace the spin and the conduction-electron dynamics on a time scale, which exceeds the characteristic electronic scale that is set by the inverse nearest-neighbor hopping by more than five orders of magnitude. This is achieved with a novel construction of absorbing boundary conditions, which employs a generalized Lindblad master-equation approach to couple the edge sites of the conduction-electron tight-binding model to an external bath. The failure of the standard Lindblad approach to absorbing boundaries is traced back to artificial excitations initially generated due to the coupling to the bath. This can be cured by introducing Lindblad parameter matrices and by fixing those matrices to perfectly suppress initial-state artifacts as well as reflections of physical excitations propagating to the system boundaries. Numerical results are presented and discussed for generic one-dimensional models of the electronic structure.
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。
