The Kondo Model with a Bulk Mass Term

TL;DR

This paper introduces two massive anisotropic spin-1/2 Kondo models with different boundary interactions, explores their integrability, and conjectures reflection S-matrices away from the free fermion point, linking them to boundary Ising models.

Contribution

It presents new massive versions of the anisotropic Kondo model with distinct boundary interactions and analyzes their integrability properties and boundary S-matrices.

Findings

Models have the same bulk sine-Gordon interactions.

At the Toulouse point, models relate to boundary Ising models.

Reflection S-matrices are conjectured away from the free fermion point.

Abstract

We introduce two massive versions of the anisotropic spin 1/2 Kondo model and discuss their integrability. The two models have the same bulk sine-Gordon interactions, but differ in their boundary interactions. At the Toulouse free fermion point each of the models can be understood as two decoupled Ising models in boundary magnetic fields. Reflection S-matrices away from the free fermion point are conjectured.