Dresden 2006 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 26: Transport - Poster Session

TT 26.8: Poster

Mittwoch, 29. März 2006, 14:30–18:30, P1

Zeeman Ratchets for Ballistic Spin Currents — •Matthias Scheid, Dario Bercioux, and Klaus Richter — Institut für Theoretische Physik, Universität Regensburg, Germany

We investigate the possiblity of creating directed spin-polarized currents in a two-dimensional electron gas (2DEG) subject to an asymmetric, spatially-periodic magnetic field and an external adiabatic rocking. Thereby we generalize concepts of quantum charge ratchets [1] to the case with spin. Due to the Zeeman term in the Hamiltonian, spin-up and spin-down electrons experience different effective potentials which can be taylored to achieve net spin currents without corresponding charge currents. We consider ballistic, coherent transport in waveguides defined on a 2DEG, where the magnetic field modulation is, e.g., induced from a periodic array of ferromagnetic stripes on top of the 2DEG.

[1] H. Linke, T. E. Humphrey, A. Löfgren, A. O. Sushkov, R. Newbury, R. P. Taylor and P. Omling, Science 286, 2314 (1999)