Condensed Matter Theory Seminar | December 09, 14:00

Perturbed integrable systems

Zala Lenarcic

Integrable systems typically exhibit non-generic transport properties. The spin 1/2 Heisenberg model is particularly rich, with ballistic transport of energy and different regimes of spin transport, including ballistic, diffusive, and super-diffusive ones. I will discuss the fate of the diffusive and super-diffusive regimes under different types of Hamiltonian perturbations and show that symmetry of perturbations can play an important role. For example, perturbations that respect the SU(2) symmetry of the isotropic Heisenberg model can cause anomalous transport behaviour even away from exact integrability. In the second part, I will focus on Markovian perturbations and propose a new Krylov space-type approach for an efficient steady-state description of weakly driven and open, nearly integrable systems. Lindblad dissipator will be used to add the most necessary conservation laws iteratively and thus increase the interpretability of stabilized non-thermal steady states.


Ljubljana
Seminar Room 0.03, ETP
Contact: Achim Rosch