Berlin 2012 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 51: Spin Excitations/ Spin Torque

MA 51.2: Vortrag

Freitag, 30. März 2012, 09:45–10:00, H 1012

Electronic transport and magnetization dynamics in realistic devices: a multiscale approach — •Simone Borlenghi^1,2, Valentin Rychkov², Cyril Petitjean³, Grégoire De Loubens², Olivier Klein², and Xavier Waintal³ — ¹Department of Material Science and Engineering, KTH-Stockholm, Sweden — ²Nanoelectronic group, SPEC, CEA-Saclay, France — ³Theory group SPSMS, CEA-Grenoble, France

We report on a theoretical model, based on Continuous Random Matrix Theory (CRMT) [1] and non equilibrium Green functions, that describes on an equal footing transport and magnetic degrees of freedom in realistic devices. Our approach offers a systematic way to perform multiscale simulations of spin transport [2] in mesoscopic systems with arbitrary geometry, connected to an arbitrary number of electron reservoirs. The model can be parametrized both with experimentally accessible parameters and ab initio calculations, and it is suitable for a large variety of materials (normal metals, ferromagnets, superconductors, semiconductors).

As an application of our model, we have coupled CRMT to a micromagnetic simulation code, in order to model a spectroscopic experiment performed on a spin torque nano oscillator. Our simulations predict correctly the selection rules for spin wave modes excited by spin torque, and give a description of the complex dynamics of the magnetization in qualitative agreement with experiments.

[1] V. Rychkov et al., Phys. Rev. Lett. 103 (2009), 066602.

[2] S. Borlenghi et al., Phys. Rev. B 84 (2011), 035412.