Ultrafast manipulation and quantum kinetics of spin decoherence in magnetic quantum dots

磁性量子点中自旋退相干的超快操纵和量子动力学

• 批准号: 40956610
• 负责人: Professor Dr. Tilmann Kuhn
• 金额: --
• 依托单位: Lehrstuhl für Theoretische Physik III (Quantentheorie der kondensierten Materie)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/40956610?language=en
• 关键词: Ultrafast; manipulation; quantum; kinetics; spin

The main objective of the project is a microscopic theoretical analysis of the ultrafast optical manipulation of spin states in magnetic quantum dot structures including the relevant relaxation and decoherence processes. In the first period we have analyzed the light-induced dynamics in an uncharged CdTe quantum dot doped with a single Mn atom. We have found that by using specific sequences of ultrashort laser pulses the spin of the Mn atom can be driven into each of its six possible orientations. Based on this successful demonstration of an optical control of the Mn spin in a quantum dot, in the following period we are planning to extend our investigations in three directions: (i) we will extend the microscopic theoretical model of the quantum dot structure in order to analyze more quantitatively features which might influence the efficiency of the spin switching dynamics; (ii) new switching protocols will be developed either to optimize the switching of the Mn spin into a specific orientation or to drive the Mn spin into well-defined quantum-mechanical superposition states; (iii) the calculations will be extended to charged quantum dot structures as well as to quantum dot structures made from different material classes, which are again doped with a single (or maybe a few) magnetic atoms.

该项目的主要目标是对磁量子点结构中自旋态的超快光学操纵进行微观理论分析，包括相关的弛豫和退相干过程。在第一阶段，我们分析了不带电的碲化镉量子点中掺杂单个锰原子的光致动力学。我们已经发现，通过使用特定序列的超短激光脉冲，Mn原子的自旋可以被驱动到其六种可能的取向中的每一种。基于这一成功的量子点Mn自旋的光学控制实验，我们计划在以下三个方面展开研究：（1）扩展量子点结构的微观理论模型，以便更定量地分析可能影响自旋转换动力学效率的特征;（ii）将开发新的切换协议，以优化Mn自旋到特定取向的切换，或者将Mn自旋驱动到明确定义的量子力学叠加态;（iii）计算将扩展到带电量子点结构以及由不同材料类别制成的量子点结构，其再次掺杂有单个（或可能几个）磁性原子。