UChicago PME Quantum Science and Engineering Seminar - Yahui Li

Highly entangled stationary states in open quantum systems 

Can entanglement persist in open quantum systems? In this talk, I will show that strong non-Abelian symmetries can generate highly entangled stationary states even under decohering quantum channels. I will present exact results for several entanglement measures of these stationary states, focusing on logarithmic negativity. For example, we find that global U(1) symmetry leads to separable stationary states, whereas global SU(2) symmetry allows the logarithmic negativity to grow logarithmically with system size. I will also discuss quantum Hilbert space fragmentation as a generalized symmetry, which possesses exponentially many non-Abelian conserved quantities and leads to a volume-law scaling of logarithmic negativity. These exact results extend to a broad range of symmetries, including finite groups, continuous symmetries, and quantum groups, illustrating how non-Abelian strong symmetry can in general stabilize entanglement in decohering environments.

Zoom: https://uchicago.zoom.us/j/91242008451?pwd=XbJnA6cebDVhvdo9TajuigSGTZDXPS.1&from=addon

Hosted by Ruben Verresen