We have studied an electron transport in inversion layers of high-mobility Si(100) samples. At high electron concentrations and temperatures below 4.2 K, two series of Shubnikov-de Haas oscillations have been observed. The temperature damping of the second series oscillations indicates that the second occupied subband belongs to the first energy level of the fourfold-degenerate ladder 0′. Samples with two occupied subbans exhibit a strong anomalous negative magnetoresitance, reaching ≈25% of a zero field value at B= 12 T. The resistance decrease is more pronounced for lower temperatures and higher electron concentrations. We explain this behaviour by an increase of the second subband mobility due to the freezing-out of the scattering of 0′ electrons. Based on the measured periods of SdH oscillations, we conclude that the electrons are distributed inhomogeneously beneath the sample gate.
@article{arxiv.cond-mat/9507136,
title = {Magnetotransport with two occupied subbands in a Si(100) inversion layer},
author = {S. G. Semenchinsky and L. Smrcka and J. Stehno},
journal= {arXiv preprint arXiv:cond-mat/9507136},
year = {2009}
}
Comments
4 pages. RevTex text and 4 PostScript figures in a single tar-compressed file produced by 'uufiles'