Condensed Matter Theory Seminar - Ruochen Ma - University of California Santa Barbara

Statistical Mechanics of the Non-Abelian Learnability Transition

Monitored many-body quantum systems can undergo sharp learnability transitions characterized by how much information can be learned by the observer. When the dynamics conserves a non-Abelian charge, such as an SU(2) spin, understanding how the observer learns the total charge remains an outstanding problem. Monitored many-body quantum systems can undergo sharp learnability transitions characterized by how much information an observer can learn. When the dynamics conserves a non-Abelian charge, such as SU(2) spin, understanding how the observer learns the total charge remains an outstanding problem. In this talk, I will describe a theory of one-dimensional monitored quantum dynamics with SU(2) symmetry and show that it can be described by an effective replicated loop model. The theory explains the scaling of entanglement and learning time found numerically and predicts that the spin-sharpening and entanglement transitions coincide as a single transition.
 

Biography: Ruochen Ma is a postdoctoral fellow at the Kavli Institute for Theoretical Physics at UCSB. He received his Ph.D. from the Perimeter Institute. He is interested in quantum dynamics and topological phases of matter.

Host: Meng Cheng