Abstract
Elucidating the phase diagram of lattice gauge theories with fermionic matter in dimensions has become a problem of considerable interest in recent years, motivated by physical problems ranging from chiral symmetry breaking in high-energy physics to fractionalized phases of strongly correlated materials in condensed matter physics. For a sufficiently large number of flavors of four-component Dirac fermions, recent sign-problem-free quantum Monte Carlo studies of lattice quantum electrodynamics () on the square lattice have found evidence for a continuous quantum phase transition between a power-law correlated conformal phase and a confining valence-bond-solid phase with spontaneously broken point-group symmetries. The critical continuum theory of this transition was shown to be the -Gross-Neveu model, equivalent to the gauged Nambu–Jona-Lasinio model, and critical exponents were computed to first order in the large- expansion and the expansion. We extend these studies by computing critical exponents to second order in the large- expansion and to four-loop order in the expansion below four spacetime dimensions. In the latter context, we also explicitly demonstrate that the discrete symmetry of the valence-bond-solid order parameter is dynamically enlarged to a continuous symmetry at criticality for all values of .
- Received 31 March 2020
- Accepted 28 April 2020
DOI:https://doi.org/10.1103/PhysRevD.101.094505
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