Anatomy of Z2 fluxes in anyon Fermi liquids and Bose condensates

TL;DR

This paper investigates the properties of pi-fluxes in anyon Fermi liquids and Bose condensates, revealing their deconfinement or confinement behavior and associated screening effects using exact lattice bosonization.

Contribution

It provides a detailed analysis of pi-flux quasiparticles in different quantum liquids, highlighting their deconfined nature in Fermi liquids and marginal confinement in Bose condensates.

Findings

Pi-flux remains deconfined in Fermi liquids with a finite energy cost.

Pi-flux binds 1/8 of a fermionic hole in Fermi gases.

Pi-flux becomes a marginally confined excitation in Bose-Einstein condensates.

Abstract

We study in detail the properties of pi-fluxes embedded in a state with a finite density of anyons that form either a Fermi liquid or a Bose-Einstein condensate. By employing a recently developed exact lattice bosonization in 2D, we demonstrate that such pi-flux remains a fully deconfined quasiparticle with a finite energy cost in a Fermi liquid of emergent fermions coupled to a Z2 gauge field. This pi-flux is accompanied by a screening cloud of fermions, which in the case of a Fermi gas with a parabolic dispersion binds exactly 1/8 of a fermionic hole. In addition there is a long-ranged power-law oscillatory disturbance of the liquid surrounding the pi-flux akin to Friedel oscillations. These results carry over directly to the pi-flux excitations in orthogonal metals. In sharp contrast, when the pi-flux is surrounded by a Bose-Einstein condensate of particles coupled to a Z2 gauge field, it binds a superfluid half-vortex, becoming a marginally confined excitation with a logarithmic energy cost divergence.