Deconfined Phases and Phase Transitions in a Simple Model

Event Dates: 

Friday, May 5, 2017 - 10:30am

CTQM Seminar Type: 

  • CTQM Seminar

Seminar Location: 

  • Duane Physics Room G126

Speaker Name(s): 

Tarun Grover

Speaker Affiliation(s): 

University of California San Diego

Abstract, Event Details: 

I will introduce a simple model that hosts several highly entangled phases and phase transitions. The basic rules of our model are simple:  fermions tunnel between sites of a square lattice and each tunneling event changes the sign of an Ising field residing on the links of the lattice.  The Ising fields are subject to a transverse magnetic field. Crucially, the model is amenable to unbiased quantum Monte Carlo simulations. We find that there exists a regime where there is no local order parameter and the low energy theory corresponds to the deconfined phase of an Ising gauge theory with fermionic matter. We also find two symmetry breaking phases, which are separated by a deconfined quantum critical point. The transition from the symmetry unbroken phase to the symmetry broken one is seemingly continuous, and calls for a field theoretical understanding that we currently do not have. Finally, motivated by this model, I will present an argument that utilizes the presence of the sign problem in a certain model to deduce a physics statement about a different model.