•D.G. Polyakov1, I.A. Dmitriev1, M.G. Vavilov2,
I.L. Aleiner3 und A.D. Mirlin1,4
3Physics Dept., Columbia University, New York, NY 10027,
USA
4Institut für Theorie der kondensierten Materie, Universität
Karlsruhe, 76128 Karlsruhe
1Institut für Nanotechnologie, Forschungszentrum Karlsruhe,
76021 Karlsruhe
2Physics Dept., Massachusetts Institute of Technology, Cambridge,
MA 02139, USA
An intriguing development in the study of magnetotransport in high-mobility
2DEGs was the observations by Zudov et al. and by Mani et al. of magnetooscillations
of the photoconductivity, evolving with increasing microwave power into
zero-resistance states. We discuss the nature of the oscillations and develop
theory which is in good agreement with the experimental data. The most
important mechanism of the oscillations [1,2] is related to a radiation-induced
change of the electron distribution function. We consider nonlinear effects,
with respect to both the dc field and the microwave power, as well as the
temperature dependence due to the inelastic relaxation. We also study [3]
the oscillations governed by quasiclassical memory effects. For low B,
this mechanism, in combination with microwave-dependent screening, may
dominate over that based on the Landau quantization. [1] I.A.Dmitriev,
A.D.Mirlin, and D.G.Polyakov, cond-mat/0304529; [2] I.A.Dmitriev, M.G.Vavilov,
I.A.Aleiner, A.D.Mirlin, and D.G.Polyakov, cond-mat/0310668; [3] I.A.Dmitriev,
A.D.Mirlin, and D.G.Polyakov, to be published.