Emergent dipole field theory in atomic ladders

TL;DR

This paper explores the phase diagram and dynamics of hard-core bosons on ladders with kinetic constraints, revealing an emergent dipole symmetry that influences slow relaxation and can be realized in cold atom and Rydberg systems.

Contribution

It introduces a paired Tomonaga-Luttinger liquid phase with emergent dipole symmetry and analyzes its effects on quench dynamics using analytical and numerical methods.

Findings

Identification of a paired Tomonaga-Luttinger liquid phase

Emergent dipole symmetry leads to slow relaxation dynamics

Proposed experimental protocols for observing these effects

Abstract

We study the dynamics of hard-core bosons on ladders, in the presence of strong kinetic constrains akin to those of the Bariev model. We use a combination of analytical methods and numerical simulations to establish the phase diagram of the model. The model displays a paired Tomonaga-Luttinger liquid phase featuring an emergent dipole symmetry, which encodes the local pairing constraint into a global, nonlocal quantity. We scrutinize the effect of such emergent low-energy symmetry during quench dynamics including single-particle defects. We observe that, despite being approximate, the dipole symmetry still leads to very slow relaxation dynamics, which we model via an effective field theory. The model we discuss is amenable to realization in both cold atoms in optical lattices and Rydberg atom arrays with dynamics taking place solely in the Rydberg manifold. To observe the unusual dynamics of excitations in such experimental platforms, we propose a two-step protocol, which starts with the quasi-adiabatic preparation of low-energy states, followed by the local creation of defects and their study under quench dynamics.