PIRSA:18060066

Video URL

https://pirsa.org/18060066

Quantum Many-Body Scarring in constrained models

Ho, W.W. (2018). Quantum Many-Body Scarring in constrained models. Perimeter Institute for Theoretical Physics. https://pirsa.org/18060066

Ho, Wen Wei. Quantum Many-Body Scarring in constrained models. Perimeter Institute for Theoretical Physics, Jun. 21, 2018, https://pirsa.org/18060066 

          @misc{ scivideos_PIRSA:18060066,
            doi = {10.48660/18060066},
            url = {https://pirsa.org/18060066},
            author = {Ho, Wen Wei},
            keywords = {Quantum Matter},
            language = {en},
            title = {Quantum Many-Body Scarring in constrained models},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2018},
            month = {jun},
            note = {PIRSA:18060066 see, \url{https://scivideos.org/index.php/pirsa/18060066}}
          }

Wen Wei Ho National University of Singapore

Talk numberPIRSA:18060066
DOI10.48660/18060066
Source RepositoryPIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

Recent quench experiments in a quantum simulator of interacting Rydberg atoms demonstrated surprising long-lived, periodic revivals from certain low entanglement states, while apparently quick thermalization from others. Motivated by these findings, I will in this talk analyze the dynamics of a family of kinetically constrained spin models related to the experiments. By introducing a manifold of locally entangled spins, representable by a low-bond dimension matrix product state (MPS), I will derive "semiclassical" equations of motion for them. I find that they host isolated, unstable periodic orbits, the presence of which captures the long-lived oscillations and gives rise to slow relaxation of local observables from certain initial configurations. This thus represents a form of weak breaking of ergodicity in dynamics. Our results are reminiscent of the phenomenon of quantum scarring in single-particle chaotic systems which is rooted in classical unstable periodic orbits, and complement the explanation of the recurrences given by [Nature Physics (2018), doi:10.1038/s41567-018-0137-5], in terms of motion over special nonergodic many-body eigenstates, suggestively dubbed `quantum many-body scars'.