Exotic Quantum Critical Points with Staggered Fermions

TL;DR

This paper investigates an exotic quantum critical point in a model with massless staggered fermions, revealing a second order phase transition without spontaneous symmetry breaking, supported by extensive three-dimensional calculations.

Contribution

It introduces a novel quantum critical point in a four-fermion interaction model with staggered fermions, challenging mean field predictions about the order of the transition.

Findings

Existence of a second order phase transition in three dimensions.

Transition remains second order in preliminary four-dimensional results.

No spontaneous symmetry breaking occurs at the critical point.

Abstract

We study two flavors of massless staggered fermions interacting via an on-site four-fermion inter- action and argue that the model contains an exotic quantum critical point separating the perturba- tive massless phase from a massive fermion phase at strong couplings where the fermion bilinear condensate remains zero. We believe that no spontaneous symmetry breaking occurs at the tran- sition. We have extensive calculations in three Euclidian dimensions that are consistent with the existence of a single second order phase transition separating the two phases. Although mean field theory suggests that this transition will turn first order at sufficiently large number of dimensions, preliminary results suggest that the transition remains second order in four-dimensions.