Is Schwinger Model at Finite Density a Crystal?

Abstract

It has been believed since the paper by Fischler, Kogut and Susskind (FKS) that in QED_2 at finite charge density the chiral condensate exhibits a spatially inhomogeneous, oscillating behaviour. In this paper we demonstrate that this inhomogeneity is due to unphysical explicit breaking of the translational invariance by a uniform background charge density. Moreover, we investigate in the context of a simple statistical model what happens if the neutralizing background is composed instead of heavy, but dynamical, particles. We find that in contrast to the standard picture of FKS, the chiral condensate will not exhibit coherent oscillations on large distance scales, unless the heavy neutralizing particles themselves form a crystal and the density is high.

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Cited by in corpus (9)

• Quarkyonic Chiral Spirals
• The half-filled Landau level: the case for Dirac composite fermions
• A Twisted Kink Crystal in the Chiral Gross-Neveu model
• Density Induced Phase Transitions in the Schwinger Model: A Study with Matrix Product States
• Massless fermions in multi-flavor QED_2
• QED at a finite chemical potential
• Renormalization of QCD_2
• Ferromagnets, a New Anomaly, Instantons, and (noninvertible) Continuous Translations
• Anomalous Continuous Translations