# Full counting statistics in the spin-1/2 Heisenberg XXZ chain

## TL;DR

This paper investigates the probability distributions of subsystem magnetization in the spin-1/2 Heisenberg XXZ chain, revealing universal scaling functions and quantifying quantum fluctuations in its critical ground state.

## Contribution

It introduces a method to determine universal scaling functions of magnetization distributions using free fermion techniques and boundary sine-Gordon model relations.

## Key findings

- Identification of scaling behavior in magnetization distributions
- Derivation of universal scaling functions
- Quantification of quantum fluctuations in the ground state

## Abstract

The spin-1/2 Heisenberg chain exhibits a quantum critical regime characterized by quasi long-range magnetic order at zero temperature. We quantify the strength of quantum fluctuations in the ground state by determining the probability distributions of the components of the (staggered) subsystem magnetization. Some of these exhibit scaling and the corresponding universal scaling functions can be determined by free fermion methods and by exploiting a relation with the boundary sine-Gordon model.