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TT: Fachverband Tiefe Temperaturen

TT 23: Nanoelectronics II - Spintronics and Magnetotransport

TT 23.6: Vortrag

Donnerstag, 29. März 2007, 10:45–11:00, H19

Spin transport in Heisenberg antiferromagnets — •Michael Sentef, Marcus Kollar, and Arno Kampf — Theoretische Physik III, Elektronische Korrelationen und Magnetismus, Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany

We study the dynamic spin conductivity of insulating antiferromagnets described by the XXZ Heisenberg model in two and three dimensions. Spin currents flow in response to a magnetic-field gradient or, in systems with spin-orbit coupling, perpendicular to a time-dependent electric field. Linear response theory provides the Kubo formula for the spin conductivity, which is then calculated within interacting spin-wave theory. We find that the dimensionality of the system plays a crucial role for the isotropic Heisenberg model: In d=3 the regular part of the spin conductivity vanishes linearly in the zero frequency limit, whereas in d=2 it approaches a finite zero frequency value.

[1] M. Sentef, M. Kollar, and A. P. Kampf, cond-mat/0612215 (2006).