Simone FRATINI
Scattering of charge carriers by slow degrees of freedom can drive an electronic system away from normal transport behavior, causing anomalously large resistivities. At the basis of this phenomenon lies the idea that localization corrections, that are known to make the conductivity vanish in disordered systems, also partially survive when the random environment is dynamical. These quantum corrections are capable of reducing the carrier conductivity below the semiclassical value, provided that the scatterers (phonons or any other collective bosonic excitation) are sufficiently slow.
The above phenomenology, dubbed "transient localization", has been thoroughly studied during the last decade. It has been succesful in explaining the anomalous transport behavior of organic semiconductors, where the role of a dynamical random environment is played by slow molecular vibrations. Because it can cause a large enhancement of the resistivity, transient localization is also a natural candidate to explain bad metal behavior. In particular, it naturally explains the emergence of Displaced Drude Peaks in the optical absorption spectra, as commonly observed in experiments in a variety of materials.
In this talk I shall review recent and ongoing work aimed at applying the concept of transient localization to correlated systems and other bad/strange metals, and discuss likely sources of dynamical disorder that could be at the origin of the phenomenon. I shall also comment on the fact that this whole phenomenon might have been overlooked so far, as it is not captured by popular approaches applied to correlated electron systems, such as Dynamical Mean Field Theory.
[2] Pseudogap metal induced by long-range Coulomb interactions K. Driscoll, A. Ralko, S. Fratini Phys. Rev. B 103, L201106 (2021) [3] Rise and fall of Landau’s quasiparticles while approaching the Mott transition A. Pustogow, Y. Saito, A. Löhle, M. Sanz Alonso, A. Kawamoto, V. Dobrosavljevic, M. Dressel and S. Fratini Nat. Commun. 12, 1571 (2021)