Fermion-Vortex Interactions in Axion Electrodynamics

TL;DR

This paper explores how a $ heta$ term in axion electrodynamics influences fermion-vortex interactions, revealing new effective interactions and flux attachment phenomena through duality and dimensional reduction.

Contribution

It introduces a relativistic model coupling scalar, fermion, and gauge fields with a $ heta$ term, deriving emergent interactions and flux attachment effects not previously detailed.

Findings

The $ heta$ term significantly alters fermion-vortex interactions.

Effective fermion-fermion and fermion-vortex interactions are derived.

Flux attachment to fermions depends on the $ heta$ parameter.

Abstract

A relativistic action for scalar condensate-fermion mixture is considered where both the scalar boson and the fermion fields are coupled to a $U(1)$ gauge field. The dynamics of the gauge field is governed by a linear combination of the Maxwell term, and the Lorentz invariant $\mathbf{E\cdot B}$ term with a constant coefficient $\theta$. We obtain an effective action describing an emergent fermion-fermion interaction and fermion-vortex tube interaction by using the particle-string duality, and find that the $\theta$ term can significantly affect the interaction of fermions and vortices. We also perform a dimensional reduction to show a $\theta$ dependent flux attachment to the itinerant fermions.