# Spin-entanglement wave in a coarse-grained optical lattice

## TL;DR

This paper investigates how coarse-graining affects the detection and understanding of entanglement spreading in spin chains, showing that some entanglement information persists even with limited resolution, which can lead to an effective classical description.

## Contribution

It introduces a coarse graining channel to analyze entanglement in spin chains and demonstrates how entanglement detection is affected by resolution levels, linking microscopic and coarse-grained descriptions.

## Key findings

- Entanglement can be detected at certain coarse graining levels.
- Entanglement decays exponentially with reduced resolution.
- Limited resolution may lead to an effective classical behavior.

## Abstract

In the present work we explore a suitable coarse graining channel as a tool to describe the effective entanglement spreading in a coarse-grained spin-chain with different degrees of resolution. Comparing it with the experimental realizations performed with ultracold atoms, our results suggest that even if we are not able to fully resolve the system, entanglement can still be detected for some coarse graining levels. Furthermore, we show that it is possible to have some information about the "microscopic" entanglement, even if we have access only to the system's coarse-grained description. We show that the amount of entanglement decays exponentially with the lack of system resolution. The lack of experimental resolution might thus lead to an effective classical description.