Magnetoresistance in semiconductor structures with hopping conductivity: effects of random potential and generalization for the case of acceptor states - Condensed Matter > Disordered Systems and Neural NetworksReportar como inadecuado




Magnetoresistance in semiconductor structures with hopping conductivity: effects of random potential and generalization for the case of acceptor states - Condensed Matter > Disordered Systems and Neural Networks - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We reconsider the theory of magnetoresistance in hopping semiconductors.First, we have shown that the random potential of the background impuritiesaffects significantly preexponential factor of the tunneling amplitude whichbecomes to be a short-range one in contrast to the long-range one for purelyCoulomb hopping centers. This factor to some extent suppresses the negativeinterference magnetoresistance and can lead to its decrease with temperaturedecrease which is in agreement with earlier experimental observations. We havealso extended the theoretical models of positive spin magnetoresistance, inparticular, related to a presence of doubly occupied states corresponding tothe upper Hubbard band to the case of acceptor states in 2D structures. Wehave shown that this mechanism can dominate over classical wave-shrinkagemagnetoresistance at low temperatures. Our results are in semi-quantitativeagreement with experimental data.



Autor: N.V. Agrinskaya, V.I. Kozub, A.V. Shumilin, E. Sobko

Fuente: https://arxiv.org/







Documentos relacionados