Emptiness formation probability of the XXZ spin-1/2 Heisenberg chain at Delta=1/2

TL;DR

This paper calculates the emptiness formation probability for the XXZ spin-1/2 Heisenberg chain at Delta=1/2 using integral representations, linking it to the enumeration of alternating sign matrices.

Contribution

It provides an explicit computation of the emptiness formation probability at a specific anisotropy, connecting quantum spin chains to combinatorial enumeration.

Findings

Emptiness formation probability expressed via alternating sign matrices.

Explicit integral representation for correlation functions.

Connection established between quantum spin models and combinatorics.

Abstract

Using a multiple integral representation for the correlation functions, we compute the emptiness formation probability of the XXZ spin-1/2 Heisenberg chain at anisotropy Delta=1/2. We prove it is expressed in term of the number of alternating sign matrices.