# Effects of indistinguishability in a system of three identical qubits

## TL;DR

This paper investigates how particle indistinguishability and measurement type influence entanglement in a system of three identical qubits, revealing that spatial overlap and measurement localization significantly affect quantum correlations.

## Contribution

It applies a non-standard approach to analyze entanglement in identical qubits, demonstrating the impact of spatial overlap and measurement localization on entanglement properties.

## Key findings

- Localized measurements treat qubits as distinguishable, showing no entanglement.
- Delocalized measurements induce measurement-based entanglement.
- Complete spatial overlap of boson qubits results in genuine three-partite entanglement.

## Abstract

Quantum correlations of identical particles are important for quantum-enhanced technologies. The recently introduced non-standard approach to treat identical particles [G. Compagno et al., Phil. Trans. R. Soc. A 376, 20170317 (2018)] is here exploited to show the effect of particle indistinguishability on the characterization of entanglement of three identical qubits. We show that, by spatially localized measurements in separated regions, three independently-prepared separated qubits in a pure elementary state behave as distinguishable ones, as expected. On the other hand, delocalized measurements make it emerge a measurement-induced entanglement. We then find that three independently-prepared boson qubits under complete spatial overlap exhibit genuine three-partite entanglement. These results evidence the effect of spatial overlap on identical particle entanglement and show that the latter depends on both the quantum state and the type of measurement.