PIRSA:25110121

Video URL

https://pirsa.org/25110121

Quantum Breakdown Model and the Exponential U(1) Symmetry

Lian, B. (2025). Quantum Breakdown Model and the Exponential U(1) Symmetry. Perimeter Institute for Theoretical Physics. https://pirsa.org/25110121

Lian, Biao. Quantum Breakdown Model and the Exponential U(1) Symmetry. Perimeter Institute for Theoretical Physics, Nov. 25, 2025, https://pirsa.org/25110121 

          @misc{ scivideos_PIRSA:25110121,
            doi = {},
            url = {https://pirsa.org/25110121},
            author = {Lian, Biao},
            keywords = {Quantum Matter},
            language = {en},
            title = {Quantum Breakdown Model and the Exponential U(1) Symmetry},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2025},
            month = {nov},
            note = {PIRSA:25110121 see, \url{https://scivideos.org/pirsa/25110121}}
          }

Biao Lian Princeton University

Talk numberPIRSA:25110121
Source RepositoryPIRSA
Collection
Talk Type Other
Subject

Abstract

I will talk about the 1D quantum breakdown model in boson and spin systems, which has an exponential U(1) symmetry with charge decaying exponentially in space. We show that the ground state of the model exhibits a phase transition from a symmetric paramagnetic phase to a quantum breakdown condensate phase that spontaneously breaks the exponential U(1) symmetry. Unconventionally, the condensate phase does not have gapless Goldstone modes, making the spontaneous symmetry breaking stable at zero temperature in 1D. The condensate phase also has an exponentially large ground state degeneracy, which resembles a quantum glass but requires no disorder. This challenges the existing classification schemes of quantum phases of matter.