Regensburg 2002 – scientific programme
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MA: Magnetismus
MA 6: Spinabhängige Transportphänomene I
MA 6.5: Talk
Monday, March 11, 2002, 16:15–16:30, H22
Spin-dependent Quantum Transport: Criterion for Adiabaticity in Disordered Mesoscopic Systems — •Markus Popp1, Diego Frustaglia2, and Klaus Richter1 — 1Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg — 2MPI für Physik Komplexer Systeme, Nöthnitzer Str. 38, 01187 Dresden
We consider spin-dependent quantum transport in mesoscopic systems with
inhomogeneous magnetic
fields. If the electron spin couples adiabatically to the spatially varying
field, the spin wave function acquires a geometrical or Berry phase that
gives rise
to effects on the ballistic magnetoconductance[1]. Using a recursive
Green’s function method we calculate transmission probabilities for
different
mesoscopic structures and address the problem how the adiabatic regime
is reached in the presence of impurities. Our numerical results provide
an answer to the controversial discussion[2,3], whether the elastic
scattering time or the Thouless time sets the relevant time scale for
adiabaticity in disordered samples.
[1] A. Stern, Phys. Rev. Lett. 68, 1022 (1992);
D. Frustaglia and K. Richter, Found. of Physics 31, 399 (2001).
[2] S.A van Langen, H.P.A. Knops, J.C.J. Paasschens,
C.W.J. Beenaker, Phys. Rev. B 59, 2102 (1999).
[3] D. Loss, H. Schöller, P. Goldbart, Phys. Rev. B 59, 13328 (1999);
H. A. Engel and D. Loss, Phys. Rev. B 62, 10238 (2000)