# How order melts after quantum quenches

## TL;DR

This paper investigates how long-range order in a quantum many-body system, specifically the spin-1/2 Heisenberg XXZ chain, melts over time after a quantum quench, revealing detailed dynamics through the distribution of the order parameter.

## Contribution

It provides the first detailed quantum mechanical distribution function of the order parameter during the melting process after a quench from the Néel state.

## Key findings

- Order melts over time after a quantum quench.
- Intermediate times show a broad probability distribution of the order parameter.
- Detailed quantum distribution functions characterize the melting process.

## Abstract

Injecting a sufficiently large energy density into an isolated many-particle system prepared in a state with long-range order will lead to the melting of the order over time. Detailed information about this process can be derived from the quantum mechanical probability distribution of the order parameter. We study this process for the paradigmatic case of the spin-1/2 Heisenberg XXZ chain. We determine the full quantum mechanical distribution function of the staggered subsystem magnetization as a function of time after a quantum quench from the classical N\'eel state. This provides a detailed picture of how the N\'eel order melts and reveals the existence of an interesting regime at intermediate times that is characterized by a very broad probability distribution.