Electronic theory of ultrafast spin dynamics

超快自旋动力学电子理论

• 批准号: 5372924
• 负责人: Professor Dr. Wolfgang Hübner
• 金额: --
• 依托单位: Arbeitsgruppe Theorie der kondensierten Materie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2002
• 资助国家: 德国
• 起止时间: 2001-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5372924?language=en
• 关键词: Electronic; theory; ultrafast; spin; dynamics

The tremendous increase in storage density and read/write speed in magnetic media is reaching its physical limits. Actual read-write processes take place in the order of nanoseconds. Newly developed methods, like precessional switching, have shown the potential to reach time scales of a hundred picoseconds, while competing non-magnetic optical technologies have already demonstrated even faster switching. Therefore, the need for an upspeed of magnetic dynamics is imminent. Thus it is the goal of this project to theoretically explore and understand the physical processes, possibilities, and limitations of spin dynamics on the subpicosecond time scale. The project will be focussed on the theoretical exploration of all-optical technologies of magnetic switching, which guarantee a contact-free mode of device operation, exploiting the relativistic and quantum nature of magnetic dynamics on ultrafast time scales. Ferromagnetic metals, antiferromagnetic transition metal oxides, and small magnetic nanoparticles will be taken as prototypical materials for this theoretical investigation. The electronic theory for the quantum mechanical description of these materials will be based on both first principles and parametrized approaches in order to be able to account for the materials science and the magneto-optical aspects of ultrafast spin dynamics simultaneously.

磁介质中存储密度和读/写速度的巨大增长正在达到其物理极限。实际的读写过程发生在纳秒级。新开发的方法，如岁差切换，已经显示出达到100皮秒时间尺度的潜力，而竞争的非磁性光学技术已经展示了更快的切换。因此，迫切需要加速磁动力学。因此，本计画的目标是从理论上探讨和了解亚皮秒时间尺度上自旋动力学的物理过程、可能性和限制。该项目将侧重于磁开关的全光技术的理论探索，该技术保证了设备操作的无接触模式，利用超快时间尺度上磁动力学的相对论和量子性质。铁磁金属、反铁磁过渡金属氧化物和小的磁性纳米颗粒将被作为本理论研究的原型材料。这些材料的量子力学描述的电子理论将基于第一原理和参数化方法，以便能够同时解释材料科学和超快自旋动力学的磁光方面。