Emergent Symmetry in a Quantum Clock Model

Speaker: Pranay Patil

When: July 11, 2019 (Thu), 11:00AM to 12:00PM (add to my calendar)
Location: SCI 352

This event is part of the Departmental Seminars.

Dissertation Committee: Anders Sandvik, Claudio Chamon, Emanuel Katz, Alex Sushkov, David Campbell

Abstract: We propose a quantum clock model on the square lattice built out of a q-state classical clock model with a quantum fluctuation (a generalization of a transverse field) added to it. We see evidence that this model is closely related to the 3D classical clock model through the standard quantum to classical mapping. For q>=5, we see a continuous phase transition and for q=5,6 we show that, at the phase transition, an emergent U(1) symmetry appears, similar to the 3D classical clock models. We address the connection that this emergent symmetry has to a second length scale within the scenario of dangerously irrelevant perturbations of the XY model. We also demonstrate the existence of a tricritical point in the case of q=4, which can be tuned by changing the form of the quantum fluctuation operator.