Exact solution of a t-J chain with impurity

TL;DR

This paper provides an exact analytical solution for a t-J chain with an integrable impurity, revealing detailed impurity effects on ground state, thermodynamics, and transport properties.

Contribution

It introduces a novel integrable impurity model in the t-J chain and derives exact results for impurity-induced changes in physical properties.

Findings

Impurity affects ground state and susceptibilities.

Existence of an impurity bound state in the holon sector.

Transport properties are modified by the impurity.

Abstract

We study the effects of an integrable impurity in a periodic t-J chain. The impurity couples to both spin and charge degrees of freedom and has the interesting feature that the interaction with the bulk can be varied continuously without losing integrability. We first consider ground state properties close to half-filling in the presence of a small bulk magnetic field. We calculate the impurity contributions to the (zero temperature) susceptibilities and the low temperature specific heat and determine the high-temperature characteristics of the impurity. We then investigate transport properties by computing the spin and charge stiffnesses at zero temperature. Finally the impurity phase--shifts are calculated and the existence of an impurity bound state in the holon sector is established.