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TT: Fachverband Tiefe Temperaturen
TT 79: Transport: Spintronics, Spincalorics and Magnetotransport (jointly with DS, HL, MA)
TT 79.4: Talk
Friday, March 24, 2017, 10:15–10:30, HSZ 03
Strong non-equilibrium effects in spin torque systems — •Tim Ludwig1, Igor S. Burmistrov2,3, Yuval Gefen4, and Alexander Shnirman1 — 1Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany — 2L.D. Landau Institute for Theoretical Physics RAS, Kosygina street 2, 119334 Moscow, Russia — 3Laboratory for Condensed Matter Physics, National Research University Higher School of Economics, 101000 Moscow, Russia — 4Department of Condensed Matter Physics, Weizmann Institute of Science, 76100 Rehovot, Israel
We consider a problem of persistent magnetization precession in a single domain ferromagnetic nano particle under the driving by the spin-transfer torque [1]. We find that the adjustment of the electronic distribution function in the particle renders this state unstable. Instead, abrupt switching of the spin orientation is predicted upon increase of the spin-transfer torque current. On the technical level, we derive an effective action of the type of Ambegaokar-Eckern-Schön action for the coupled dynamics of magnetization (gauge group SU(2)) and voltage (gauge group U(1)).
[1] T. Ludwig, I. S. Burmistrov, Y. Gefen, and A. Shnirman, arXiv:1610.09944 (2016)