A new approach to transport coefficients in the quantum spin Hall effect and to purely linear response of the quantum Hall current

par Dr Giovanna Marcelli (SISSA)

vendredi 10 déc. 2021, 14:00 → 15:00 Europe/Paris

Fokko du Cloux (Braconnier)

Using recently developed tools from space-adiabatic perturbation theory, in particular the construction of a non-equilibrium almost-stationary state, we derive general formulas for spin conductivity and show that the Kubo formula for the Hall conductivity remains valid beyond the linear response regime.

For the spin transport, we consider both the choice of the conventional and of the proper spin current operator, and we isolate a subclass of discrete periodic models (including the Kane-Mele model) where the conventional and the proper spin conductivity agree. 

These results are proved in the following framework, including both discrete and continuum models: the perturbation to a periodic spectrally gapped equilibrium one-particle Hamiltonian is modeled by a linear potential.

This seminar is based on joint works with D. Monaco, G. Panati and S. Teufel.