Transport and magnetization dynamics in semimagnetic quantum dots

半磁性量子点中的输运和磁化动力学

• 批准号: 129003436
• 负责人: Professorin Dr. Daniela Pfannkuche
• 金额: --
• 依托单位: I. Institut für Theoretische Physik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/129003436?language=en
• 关键词: Transport; magnetization; dynamics; semimagnetic; quantum

Aim of this project is a determination and characterization of nonequilibrium dynamical regimes in quantum dots made from ferromagnetic semiconductors relevant for future spintronic devices. We study both small and large quantum dots with the goal to work out a unified theoretical picture from small to large length scales. In the last funding period we developed a stochastic description of current induced magnetization switching that takes into account nonequilibrium spin noise and obtained a statistical distribution of switching times. In an extension of this work we plan to include the effect of randomness in the electronic distribution caused by scattering potentials and electron-electron interaction on the statistical distribution of the Gilbert damping parameter. Incorporating this randomness in a stochastic version of the Landau-Lifshits-Gilbert equation we will investigate its influence on magnetization dynamics and noise. For small quantum dots the effect of electron-electron interaction on magnetization relaxation and decoherence is even more pronounced as we could demonstrate in the previous funding period. We will extend these calculations to investigate the interplay of correlated intrinsic quantum dynamics and external driving by simulating pulsed bias voltages and photo-excitations.

本计画的目的是探讨铁磁半导体量子点的非平衡态动力学机制，并将其应用于未来的自旋电子元件。我们研究了小的和大的量子点，目标是从小到大的长度尺度上得出一个统一的理论图像。在上一个资助期，我们开发了一个随机描述的电流感应磁化开关，考虑到非平衡自旋噪声，并获得了统计分布的开关时间。在这项工作的延伸，我们计划包括随机性的影响，在电子分布所造成的散射势和电子-电子相互作用的统计分布的吉尔伯特阻尼参数。在Landau-Lifshits-吉尔伯特方程的随机版本中描述这种随机性，我们将研究其对磁化动力学和噪声的影响。对于小量子点，电子-电子相互作用对磁化弛豫和退相干的影响更加明显，正如我们在前一个资助期所证明的那样。我们将扩展这些计算，通过模拟脉冲偏置电压和光激发来研究相关的内在量子动力学和外部驱动的相互作用。