Spin and orbital effects in a 2d electron gas in a random magnetic field
Abstract
Using the method of superbosonization we consider a model of a random magnetic field (RMF) acting on both orbital motion and spin of electrons in two dimensions. The method is based on exact integration over one particle degrees of freedom and reduction of the problem to a functional integral over supermatrices Q(r,r^{'}) . We consider a general case when both the direction of the RMF and the g factor of the Zeeman splitting are arbitrary. Integrating out fast variations of Q we come to a standard collisional unitary nonlinear σ model. The collision term consists of purely orbital, spin, and some mixed parts. For a particular problem of a fixed direction of RMF, we show that additional soft excitations identified with spin modes should appear. Considering δ correlated weak RMF and putting g=2 we find the transport time τ_{tr} . This time is two times smaller than that for spinless particles.
 Publication:

Physical Review B
 Pub Date:
 November 2004
 DOI:
 10.1103/PhysRevB.70.195326
 arXiv:
 arXiv:condmat/0406171
 Bibcode:
 2004PhRvB..70s5326E
 Keywords:

 72.15.Rn;
 73.20.Fz;
 73.23.Ad;
 Localization effects;
 Weak or Anderson localization;
 Ballistic transport;
 Condensed Matter  Disordered Systems and Neural Networks;
 Condensed Matter  Mesoscopic Systems and Quantum Hall Effect
 EPrint:
 9 pages, no figures