On the possibility to estimate the mobility edge position for charge carriers using single-particle averages
Y.V. Skrypnyk1 and V.M. Loktev1,2
1Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine 14-b Metrolohichna Str., Kyiv 03143, Ukraine
2National Technical University of Ukraine “KPI”, 37 Peremohy Ave., Kyiv 03056, Ukraine
Received March 12, 2018
Dependence of the mobility edge position on the impurity concentration that is realized under the electronic band structure transformation is considered in a disordered system described by the Lifshitz model. Evolution of the concentrational dynamics of the mobility edge position caused by varying the threshold parameter in the Ioffe–Regel criterion is analyzed. It is demonstrated that the critical impurity concentration, which triggers the band structure trans-formation, changes slightly with varying this parameter, while the corresponding mobility edge position at this concentration remains stable. Preconditions required for the existence of concentration intervals, within which the mobility edge is shifted in proportion to the cubic root of the impurity concentration, are discussed.
PACS: 71.23.An Theories and models; localized states;
Key words: disordered system, Lifshitz model, mobility threshold, Green’s function.
Published online: May 28, 2018