Physics Colloquium: Thermalization, Transport, and signatures of Quantum Chaos in Complex Materials

Abstract:

The Boltzmann-Drude picture of electronic transport ceases to be valid when the electron mean-free-path becomes shorter than the Fermi wavelength. The Mott-Ioffe-Regel limit is defined where the two lengths are equal, and beyond it metallic transport becomes incoherent. Most experimental works have focused on the electronic transport, aiming to shed light on the anomalous behavior of the resistivity. However, careful analyses of thermal transport on complex insulators and on strongly correlated electron systems hosted in similar complex crystal structures suggest that quantum chaos may be a good description for thermalization processes in these material systems, particularly in the high temperature regime where the many phonon bands and their interactions dominate the thermal transport. While both, electron and phonon relaxations are controlled by a universal Planckian time scale \tau~\hbar/k_BT, we argue that only the thermal (energy) transport describes chaos diffusivity.

Event Organizer: Dr. Ishay Pomerantz