# Thermodynamic limit of the two-spinon form factors for the zero field XXX chain

## TL;DR

This paper introduces a method using algebraic Bethe ansatz to derive explicit form factors for quantum spin chains in the thermodynamic limit, confirming known two-spinon results for the XXX chain.

## Contribution

It provides a new algebraic Bethe ansatz-based approach to compute form factors, reproducing and extending previous results for the XXX Heisenberg chain.

## Key findings

- Explicit formulas for two-spinon form factors derived
- Method confirms previous results obtained via q-vertex operators
- Applicable to thermodynamic limit of quantum spin chains

## Abstract

In this paper we propose a method based on the algebraic Bethe ansatz leading to explicit results for the form factors of quantum spin chains in the thermodynamic limit. Starting from the determinant representations we retrieve in particular the formula for the two-spinon form factors for the isotropic XXX Heisenberg chain obtained initially in the framework of the $q$-vertex operator approach.