Transport and magnetization dynamics in semimagnetic quantum dots

• Applicant: Professorin Dr. Daniela Pfannkuche
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2009 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 129003436

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.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1285: Semiconductor Spintronics
• Participating Person: Privatdozent Dr. Alexander Chudnovskiy