Hidden quasilocal charges and Gibbs ensemble in a Lindblad system

Abstract

We consider spin-1/2 chains with external driving that breaks the continuous symmetries of the Hamiltonian. We introduce a family of models described by the Lindblad equation with local jump operators. The models have hidden strong symmetries in the form of quasilocal charges, leading to multiple nonequilibrium steady states. We compute them exactly in the form of matrix-product operators and argue that they are the analogues of quantum many-body scars in the Lindbladian setting. We observe that the dynamics leads to the emergence of a Gibbs ensemble constructed from the hidden charges.