Condensed Matter Seminar Series

Tobias Holder

Tel Aviv University

New and old transport phenomena under the perspective of Quantum geometry

Recently, the quantum geometry of the Hilbert space has attracted increasing attention for its versatility in elucidating novel transport features and correlated insulating and superconducting phases in 2d materials and van-der-Waals heterostructures. At the same time, for response theory geometric effects are challenging because they are intrinsically linked to a multiband perspective.

In this talk, I will present a new framework which connects the concepts of anomalous motion, coherent interband transitions, and wavepacket deformations. I show in which cases the Green-Kubo formalism can be continued to zero frequency to recover the Boltzmann kinetic approach and discuss some novel phenomena in the nonlinear conductivity, as well as offering new perspectives on the old question of what quantifies the dielectric response in insulators.