Generalized Landau Paradigm for Quantum Phases and Phase Transitions

Speaker: Xie Chen (California Institute of Technology)
Series: Isaac Newton Institute Seminar Series
Note: MMBW03 - Structure of entanglement

The Landau paradigm is a central dogma for understanding phase and phase transitions in condensed matter systems, yet for decades, it has been known that a variety of quantum phases and transitions exist beyond the framework. In this talk, we discuss how the recently developed notion of generalized symmetry and the Symmetry Topological Field Theory framekwork point to a way to extend the Landau paradigm. In the generalized framework, beyond-Landau phases and transitions are attributed to the breaking of generalized symmetries, which in 1+1D often do not form a group and are called noninvertible symmetries. We discuss how Landau's philosophy can be applied to the symmetry-breaking transitions of noninvertible symmetries in 1+1D, such that a field theory description of the transition can be formulated based on the fluctuation of local order parameters.