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TT: Fachverband Tiefe Temperaturen
TT 11: Transport: Nanoelectronics I - Quantum Dots and Wires, Point Contacts 2
TT 11.4: Vortrag
Montag, 23. März 2009, 14:45–15:00, HSZ 301
Resonant spin pumping with spin-orbit coupling — Markus Jerger1, •Valentina Brosco1, Pablo San José2,1, Gergely Zarand3, Alexander Shnirman4, and Gerd Schön1 — 1Institut für Theoretische Festkörperphysik , Universität Karlsruhe, Karlsruhe, Germany — 2Department of Physics, Lancaster University, Lancaster, United Kingdom — 3Theoretical Physics Department, Budapest University of Technology and Economy, Budapest, Hungary — 4Institut der Theorie der Kondersierten Materie, Universität Karlsruhe, Karlsruhe, Germany
Adiabatic particle transport in a periodic potential cyclically modulated in time was first proposed by Thouless [1]. Since then, due to to its fundamental interest in relation with the theory of geometric phases and to possible applications in metrology, charge pumping has been studied in a variety of mesoscopic devices. More recently, various authors considered pumping of spin in semiconductor nanostructures.
In the present work we discuss spin pumping in a quantum dot with spin-orbit coupling using a scattering matrix approach [2]. First, we present a general analysis of spin and charge pumping based on the symmetries of the scattering matrix. Then, we focus on spin pumping in the resonant transport regime, we calculate explicitly the pumped spin and charge for some specific pumping cycles and we analyze the conditions to have pure spin currents.
[1] D. J. Thouless, Phys. Rev. B 27, 6083 (1983).
[2] M. Büttiker, H. Thomas and A. Prêtre Z. Phys. B 94, 133 (1994); P. W. Brouwer, Phys. Rev. B 58, R10135 (1998).