The integrable open XXZ chain with broken Z_2 symmetry

TL;DR

This paper explores the integrability of the open XXZ spin chain with broken Z_2 symmetry due to boundary sources and sinks, addressing challenges in solving the model without arrow-reversal symmetry.

Contribution

It develops methods to analyze the integrable open XXZ chain with broken Z_2 symmetry, extending solutions beyond traditional Bethe Ansatz techniques.

Findings

Identifies the impact of boundary sources and sinks on integrability.

Proposes new approaches to solve models lacking arrow-reversal symmetry.

Enhances understanding of boundary effects in quantum spin chains.

Abstract

The hamiltonian of an asymmetric diffusion process with injection and ejection of particles at the ends of a chain of finite length is known to be relevant to that of the spin-1/2 XXZ chain with integrable boundary terms. However, the inclusion of boundary sources and sinks of particles breaks the arrow-reversal symmetry necessary for solution via the usual Bethe Ansatz approach. Developments in solving the model in the absence of arrow-reversal symmetry are discussed.