Regensburg 2013 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 20: Transport: Spincaloric Transport (jointly with MA)
TT 20.13: Vortrag
Montag, 11. März 2013, 18:15–18:30, H22
Origin of the spin Seebeck effect in thin films — •Michael Schreier1, Akashdeep Kamra2, Mathias Weiler1, Rudolf Gross1, and Sebastian T.B. Goennenwein1 — 1Walther-Meißner-Institut, Garching, Germany — 2Kavli Institute of Nanoscience, Delft University of Technology, The Netherlands
The spin Seebeck effect (SSE) originates from a finite temperature difference Δ T between the magnons in a ferromagnet (FM) and the electrons in a normal metal (NM) which supposedly stems from weak magnon-phonon interaction and different boundary conditions on phonon and magnon mediated heat currents. Also, recent experiments [1] suggest that the magnon-phonon interaction is much stronger than originally assumed, which again reduces the expected SSE [2]. Hence the established theory can not account quantitatively for the longitudinal SSE signals in thin films. A factor that has, however, been neglected so far is the Kapitza resistance which leads to an additional contribution to Δ T by introducing a discontinuity in the phonon temperature distribution at the FM/NM interface. This has been modelled using an analytical model and 3D finite elements simulations which show that, for thin layers, the contribution to Δ T originating from the Kapitza resistance is indeed of the same order of magnitude as the one from the original model. Hence the acoustic properties of the FM and NM play an important role in the origin of the SSE. This work is supported by the DFG via SPP1538.
[1] M. Agrawal et al., arXiv (2012)
[2] M. Weiler et al., Phys. Rev. Lett. 108, 106602 (2012)