Measurement-Protected Order in Monitored Quantum Circuits with Continuous Symmetry

          @misc{ scivideos_PIRSA:22060051,
            doi = {10.48660/22060051},
            url = {https://pirsa.org/22060051},
            author = {Hauser, Jacob},
            keywords = {Other Physics},
            language = {en},
            title = {Measurement-Protected Order in Monitored Quantum Circuits with  Continuous Symmetry},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2022},
            month = {jun},
            note = {PIRSA:22060051 see, \url{https://scivideos.org/index.php/pirsa/22060051}}
          }
          

Abstract

Monitored quantum circuits, composed of local unitary operators and projective measurements, have recently emerged as a rich setting for studying non-equilibrium quantum dynamics. In such systems, sufficient densities of measurements can protect a highly-monitored steady state phase with area law entanglement. Furthermore, it has been shown that such area law phases can host a measurement-protected Ising ferromagnetic order. However, it is not yet known whether such measurement-protected order is a generic phenomenon or whether it relies on the discrete Ising symmetry. To begin answering this question, we introduce a circuit model with continuous symmetry where ferromagnetic order arises in the steady state. Notably, our model requires feedback based on measurement results in order to generate this ferromagnetic order