Breakdown of the generalized Gibbs ensemble for current-generating quenches

Understand

We establish a relation between two hallmarks of integrable systems: the relaxation towards the generalized Gibbs ensemble (GGE) and the dissipationless charge transport.

• We show that the former one is possible only if the so called Mazur bound on the charge stiffness is saturated by local conserved quantities.
• As an example we show how a non--GGE steady state with a current can be generated in the one-dimensional model of interacting spinless fermions with a flux quench.
• Moreover an extended GGE involving the quasi-local conserved quantities can be formulated for this case.