Disorder-driven metal-insulator transitions in deformable lattices
Abstract
We show that in presence of a deformable lattice potential, the nature of the disorder-driven metal-insulator transition (MIT) is fundamentally changed with respect to the non-interacting (Anderson) scenario. For strong disorder, even a modest electron-phonon interaction is found to dramatically renormalize the random potential, opening a mobility gap at the Fermi energy. This process, which reflects disorder-enhanced polaron formation, is here given a microscopic basis by treating the lattice deformations and Anderson localization effects on the same footing. We identify an intermediate "bad insulator" transport regime which displays resistivity values exceeding the Mott-Ioffe-Regel limit and with a negative temperature coefficient, as often observed in strongly disordered metals. Our calculations reveal that this behavior originates from significant temperature-induced rearrangements of electronic states due to enhanced interaction effects close to the disorder-driven MIT.
Keywords
Cite
@article{arxiv.1604.07816,
title = {Disorder-driven metal-insulator transitions in deformable lattices},
author = {Domenico Di Sante and Simone Fratini and Vladimir Dobrosavljević and Sergio Ciuchi},
journal= {arXiv preprint arXiv:1604.07816},
year = {2017}
}
Comments
5 pages, 4 figures, revised version accepted in Phys. Rev. Lett