The Folded Spin-1/2 XXZ Model: II. Thermodynamics and Hydrodynamics with a Minimal Set of Charges

TL;DR

This paper develops a thermodynamic and hydrodynamic framework for the folded spin-1/2 XXZ model, revealing discontinuities in local observable profiles at macrostate junctions in the ballistic limit.

Contribution

It introduces a thermodynamic Bethe Ansatz and generalized hydrodynamics for the model, highlighting novel discontinuity phenomena in local observable profiles.

Findings

Discontinuities occur at macrostate junctions in the ballistic limit.

A thermodynamic Bethe Ansatz description is formulated for the model.

Generalized hydrodynamics captures the leading-order behavior of the system.

Abstract

We study the (dual) folded spin-1/2 XXZ model in the thermodynamic limit. We focus, in particular, on a class of local macrostates that includes Gibbs ensembles. We develop a thermodynamic Bethe Ansatz description and work out generalised hydrodynamics at the leading order. Remarkably, in the ballistic scaling limit the junction of two local macrostates results in a discontinuity in the profile of essentially any local observable.