We show that, in the presence of a deformable lattice potential, the nature of the disorder-driven metal-insulator transition is fundamentally changed with respect to the noninteracting (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 metal-insulator transition.

Di Sante, D., Fratini, S., Dobrosavljević, V., Ciuchi, S. (2017). Disorder-Driven Metal-Insulator Transitions in Deformable Lattices. PHYSICAL REVIEW LETTERS, 118(3), 036602-036602 [10.1103/PhysRevLett.118.036602].

Disorder-Driven Metal-Insulator Transitions in Deformable Lattices

Di Sante, D.
Primo
;
2017

Abstract

We show that, in the presence of a deformable lattice potential, the nature of the disorder-driven metal-insulator transition is fundamentally changed with respect to the noninteracting (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 metal-insulator transition.
2017
Di Sante, D., Fratini, S., Dobrosavljević, V., Ciuchi, S. (2017). Disorder-Driven Metal-Insulator Transitions in Deformable Lattices. PHYSICAL REVIEW LETTERS, 118(3), 036602-036602 [10.1103/PhysRevLett.118.036602].
Di Sante, D.; Fratini, S.; Dobrosavljević, V.; Ciuchi, S.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/871516
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