Open AccessZeeman ratchets for ballistic spin currents
Author(s) -
Scheid Matthias,
Wimmer Michael,
Bercioux Dario,
Richter Klaus
Publication year - 2007
Publication title -
physica status solidi c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 46
eISSN - 1610-1642
pISSN - 1862-6351
DOI - 10.1002/pssc.200672835
Subject(s) - zeeman effect , adiabatic process , condensed matter physics , physics , magnetic field , electron , spin (aerodynamics) , ballistic conduction , hamiltonian (control theory) , ferromagnetism , fermi gas , quantum mechanics , mathematical optimization , mathematics , thermodynamics
We investigate the possiblity of creating directed spin‐polarized currents in a two‐dimensional electron gas (2DEG) subject to an asymmetric magnetic field and an external adiabatic driving. We thereby generalize concepts of quantum charge ratchets to the case with spin. Due to the Zeeman term in the Hamiltonian, spinup and ‐down electrons experience different effective potentials, which can be tailored to achieve net spin currents without corresponding charge currents. We consider ballistic, coherent transport in waveguides defined in a 2DEG, where the magnetic field modulation is induced by ferromagnetic stripes on top of the 2DEG. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)