Disorder-induced polarons in strongly disordered metals (and doped oxides)

Sergio Ciuchi (U L'Aquila)

Dec 11. 2019, 09:40 — 10:20

The nature of the disorder-driven metal-insulator transition is fundamentally changed with respect to the noninteracting Anderson scenario when the interaction of electron with lattice is taken into account. 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. [1,2] In the strongly disordered metallic phase the change of sign of the temperature coefficient of resistivity is a signature of the onset of a disorder-induced polaronic phase. This phenomenon though physically distinct to Anderson localization, still realizes early seminal ideas of Anderson himself, concerning the interplay of disorder and lattice deformations. [3] In this talk I will present theoretical methods we have developed to address these issue and I will compare our findings with a large collection of transport on metallic alloys. I will also give some arguments to apply the mechanism illustrated here to any different “deformable” medium different than atomic such as electronic, or magnetic that is able to locally respond to disorder. ------------------------------------ [1] Domenico Di Sante and Sergio Ciuchi "Strong interplay between electron-phonon interaction and disorder in low-doped systems" Phys. Rev. B 90, 075111 (2014); -- [2] Domenico Di Sante, Simone Fratini, Vladimir Dobrosavljević, and Sergio Ciuchi "Disorder-driven metal-insulator transitions in deformable lattices" Phys. Rev. Lett 118 036602 (2017); -- [3] S. Ciuchi, D. Di Sante, V. Dobrosavljević and S. Fratini "The origin of Mooij correlations in disordered metals" npj Quantum Materials 3, 44 (2018)

Further Information
Venue:
ESI Boltzmann Lecture Hall
Associated Event:
Polarons in the 21st Century (Workshop)
Organizer(s):
Jozef Devreese (U Antwerpen)
Cesare Franchini (U Vienna)
Georg Kresse (U Vienna)
Jacques Tempere (U Antwerpen)