Anderson-like impurity in the one-dimensional t-J model: formation of local states and magnetic behaviour

TL;DR

This paper presents an exactly solvable model of an Anderson-like impurity in a one-dimensional t-J chain, revealing how impurity states and magnetic responses depend on hybridization and excitations.

Contribution

It introduces an integrable model allowing control over impurity coupling and spectrum, and analyzes impurity states and magnetic behavior using exact solutions.

Findings

Holon and spinon bound states emerge with varying hybridization.

Kondo-like magnetic response observed when parameters align with excitation scales.

Impurity contribution to thermodynamics depends on magnetic field and hybridization.

Abstract

We consider an integrable model describing an Anderson-like impurity coupled to an open $t$--$J$ chain. Both the hybridization (i.e. its coupling to bulk chain) and the local spectrum can be controlled without breaking the integrability of the model. As the hybridization is varied, holon and spinon bound states appear in the many body ground state. Based on the exact solution we study the state of the impurity and its contribution to thermodynamic quantities as a function of an applied magnetic field. Kondo behaviour in the magnetic response of the impurity can be observed provided that its parameters have been adjusted properly to the energy scales of the holon and spinon excitations of the one-dimensional bulk.