The Supersymmetric t-J Model with a Boundary

TL;DR

This paper investigates an open supersymmetric t-J chain with boundary fields using Bethe Ansatz, analyzing ground states, boundary susceptibilities, and boundary-bound states of holons, revealing how boundaries influence excitations.

Contribution

It provides a detailed analysis of boundary effects in the supersymmetric t-J model, including boundary bound states and exact boundary S-matrices, which were not previously characterized.

Findings

Boundary susceptibilities depend on boundary fields.

Holons can form boundary bound states under strong boundary fields.

Exact boundary S-matrices describe boundary effects on excitations.

Abstract

An open supersymmetric t-J chain with boundary fields is studied by means of the Bethe Ansatz. Ground state properties for the case of an almost half-filled band and a bulk magnetic field are determined. Boundary susceptibilities are calculated as functions of the boundary fields. The effects of the boundary on excitations are investigated by constructing the exact boundary S-matrix. From the analytic structure of the boundary S-matrices one deduces that holons can form boundary bound states for sufficiently strong boundary fields.