Abstract: While generic dissipative environment can be destructive to entanglement, we find that the presence of strong non-Abelian symmetries can lead to highly entangled stationary states even for unital quantum channels. We derive exact expressions for the bipartite logarithmic negativity, Rényi negativities, and operator space entanglement for stationary states restricted to one symmetric subspace, with focus on the trivial subspace. As Abelian examples, we show that strong U(1) symmetries and classical fragmentation lead to separable stationary states in any symmetric subspace. In contrast, for non-Abelian SU(N) symmetries, both logarithmic and Rényi negativities scale logarithmically with system size. For quantum fragmentation, the logarithmic negativity can even scale as a volume law. Our analytic results apply to a broad class of symmetries, including finite groups, continuous groups generated by Lie algebras, and quantum groups.

Ref: https://arxiv.org/abs/2406.08567

Bio: Yahui is a senior PhD student working with Prof. Frank Pollmann. They are interested in the effect of symmetries and constraints in quantum many-body dynamics. Currently, they are studying the entanglement dynamics in open systems as well as hydrodynamics in random circuits.