# Robust entanglement preparation against noise by controlling spatial indistinguishability

## TL;DR

This paper demonstrates that controlling spatial indistinguishability in identical particle systems can protect entanglement from noise, enabling reliable quantum state preparation despite unavoidable imperfections.

## Contribution

It introduces an entropic measure of spatial indistinguishability and shows its role in shielding entanglement from noise within the sLOCC framework.

## Key findings

- Spatial indistinguishability can preserve entanglement under noise.
- Partial indistinguishability guarantees Bell inequality violations.
- Particle identity acts as a control for noise-resistant entanglement.

## Abstract

Initialization of composite quantum systems into highly entangled states is usually a must to allow their use for quantum technologies. However, the presence of unavoidable noise in the preparation stage makes the system state mixed, thus limiting the possibility of achieving this goal. Here we address this problem in the context of identical particle systems. We define the entanglement of formation for an arbitrary state of two identical qubits within the operational framework of spatially localized operations and classical communication (sLOCC). We then introduce an entropic measure of spatial indistinguishability under sLOCC as an information resource. We show that spatial indistinguishability, even partial, may shield entanglement from noise, guaranteeing Bell inequality violations. These results prove the fundamental role of particle identity as a control for efficient noise-protected entanglement generation.