Regensburg 2002 – wissenschaftliches Programm
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MA: Magnetismus
MA 7: Spinabhängige Transportphänomene II
MA 7.7: Vortrag
Dienstag, 12. März 2002, 11:00–11:15, H22
Assisted Tunneling and Spin Fluctuations in Ferromagnetic Tunnel Junctions — •Christian Schmidt, Jens Siewert, and Klaus Richter — Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg
In recent experiments on ferromagnetic tunnel junctions, a pronounced
zero-bias anomaly has been found [1]. This phenomenon
strongly suggests a coupling of the tunneling electrons to other
degrees of freedom.
In mesoscopic systems, it is well known how to describe single-electron tunneling assisted by the bosonic degrees of freedom of an electromagnetic environment, the so-called P(E) theory [2]. In particular, this approach explains the zero-bias anomalies found in the I−V characteristics of mesoscopic tunnel junctions.
We propose an analogous description for assisted tunneling between ferromagnetic electrodes with spin-wave excitations representing the bosonic environment.
[1] S. Kreuzer, PhD Thesis, University of Regensburg, 2001.
[2] G.L. Ingold and Yu.V. Nazarov, in Single Charge Tunneling, edited by H. Grabert and M.H. Devoret (Plenum, New York, 1992), Chap.2.