Confinement and lattice QED electric flux-tubes simulated with ultracold atoms

TL;DR

This paper proposes a method to simulate 2+1-dimensional lattice QED using ultracold atoms in optical lattices, enabling the study of electric flux-tubes and confinement phenomena through measurable density fluctuations.

Contribution

It introduces a novel simulation approach for lattice QED with ultracold atoms, mapping gauge fields to BEC phases and electric fields to number fluctuations, and demonstrates confinement effects.

Findings

Electric flux-tubes and confinement observed in strong coupling limit

Density fluctuations of BECs serve as measurable indicators

Effective gauge-invariant Hamiltonian derived from ultracold atom system

Abstract

We propose a method for simulating 2+1-d compact lattice quantum-electrodynamics (QED), using ultracold atoms in optical lattices. In our model local Bose-Einstein condensates' phases correspond to the electromagnetic vector-potential, and the fluctuations of the local number operators represent the conjugate electric field. The gauge invariant Kogut-Susskind Hamiltonian is obtained as an effective low energy theory. The field is then coupled to external static charges. We show that in the strong coupling limit this gives rise to 'electric flux-tubes' and to confinement. The effect can be observed by measuring the local density fluctuations of the BECs.