Theory of Electron Transport near Anderson-Mott Transitions

Abstract

We present a theory of the DC electron transport in insulators near Anderson-Mott transitions under the influence of coexisting electron correlation and randomness. At sufficiently low temperatures, the DC electron transport in Anderson-Mott insulators is determined by the single-particle density of states (DOS) near the Fermi energy. Anderson insulators, caused by randomness, are characterized by a nonzero DOS at the Fermi energy. However, recently, the authors proposed that coexisting randomness and short-ranged interaction in insulators open a soft Hubbard gap in the DOS, and the DOS vanishes only at the Fermi energy. Based on the picture of the soft Hubbard gap, we derive a formula for the critical behavior for the temperature dependence of the DC resistivity. Comparisons of the present theory with experimental results of electrostatic carrier doping into an organic conductor kappa-(BEDT-TTF)_2Cu[N(CN)_2]Br demonstrate the evidence for the present soft-Hubbard scaling.

arXiv comment4 pages, 4 figures, 1 table

References in corpus (9)

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• Impurity Effect on the In-plane Penetration Depth of the Organic Superconductors $\kappa$-(BEDT-TTF)${}_{2}X$ ($X$ = Cu(NCS)${}_2$ and Cu[N(CN)${}_2$]Br)
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