Séminaire du LPTMS: Maurizio Fagotti

Intermediate-time dynamics in  out-of-equilibrium spin chains

Maurizio Fagotti (LPT-ENS, Paris)

I discuss some aspects of quench dynamics in quantum many-body systems. In the first part of the talk, I present an unusual mechanism of prethermalization. This is based on the presence of a symmetry of the pre-quench Hamiltonian which is spontaneously broken at zero temperature and is explicitly broken by the post-quench Hamiltonian. In the second part of the talk, I focus on the non-equilibrium time evolution of piecewise homogeneous states. The inhomogeneity of the initial state gives rise to a peculiar intermediate-time dynamics that is captured by a hydrodynamic description. I present the solution to the dynamics in the XXZ spin-1/2 chain and describe some remarkable properties of the profiles of charges and currents.
References:

V. Alba and M. Fagotti, Prethermalization at low temperature: the scent of a spontaneously broken symmetry, arXiv:1701.05552 (2017).
B. Bertini, M. Collura, J. De Nardis, and M. Fagotti, Transport in Out-of-Equilibrium XXZ Chains: Exact Profiles of Charges and Currents, Phys. Rev. Lett. 117, 207201 (2016).

Date/Time : 18/04/2017 - 11:00 - 12:00

Location : LPTMS, salle 201, 2ème étage, Bât 100, Campus d'Orsay