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HAIT Journal of Science and Engineering Volume 1, Issue 2, pp. 241-250 © 2004 Holon Academic Institute of Technology | ||||||
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Lifting of the Landau level degeneracy in 2D electron gas by point impuritiesPavel Grigoriev1,*, Alexander M. Dyugaev1,2,
and Yuri N. Ovchinnikov1,2
1L.D. Landau Institute for Theoretical Physics, | Chernogolovka, Moscow region 142432, Russia 2Max-Planck-Institut for the Physics of Complex Systems, Dresden D-01187 Germany *Corresponding author: pashag@itp.ac.ru Received 20 October 2003, revised 14 April 2004, accepted 6 May 2004
| We study the two-dimensional electron gas in magnetic field with scattering on point impurities uniformly distributed in the sample. We show that the electron-impurity interaction completely lifts the Landau level degeneracy even at low impurity concentration. This statement is in contradiction with the previous results obtained (F. Wegner, Z. Phys. B 51, 279 (1983); E. Brezin, D.I. Gross, and C. Itzykson, Nucl. Phys. B 235, 24 (1984); W. Apel, J. Phys. C 20, L577 (1987); Y. Avishai, M. Ya. Azbel and S.A. Gredeskul, Phys. Rev. B 48, 17280 (1996); S.A. Gredeskul, M. Zusman, Y. Avishai, and M.Ya. Azbel, Phys. Rep. 288, 223 (1997)) in the unphysical approximation of two-dimensional impurities. We calculate the density of states in the self-consistent approximation taking into account multiple impurity scattering. There is a large region of the electron energy w, measured from a Landau level, where the density of states r(w) is inversely proportional to |w| and proportional to the impurity concentration. Our results are applicable to different 2D electron systems as heterostructures, inversion layers and interfaces of condensed media.
___________________ | Presented at International Workshop Frontiers in Science and Technology. Holon Academic Institute of Technology, Holon, Israel, 26-27 October 2003 |