Quantum nonlocality of massive qubits in a moving frame

TL;DR

This paper investigates how quantum nonlocality of massive qubits is affected by Lorentz transformations in a moving frame, revealing that some entangled states lose nonlocality while others remain robust.

Contribution

It demonstrates that two-qubit nonmaximally entangled states can become local under Lorentz boosts, whereas three-qubit states like GHZ remain nonlocal, highlighting state-dependent relativistic effects.

Findings

Two-qubit nonlocality can be suppressed by Lorentz transformations.

GHZ states maintain nonlocality under all Lorentz boosts.

W states may admit local-hidden-variable models in certain conditions.

Abstract

We perform numerical tests on quantum nonlocality of two-level quantum systems (qubits) observed by a uniformly moving observer. Under a suitable momentum setting, the quantum nonlocality of two-qubit nonmaximally entangled states could be weakened drastically by the Lorentz transformation allowing for the existence of local-hidden-variable models, whereas three-qubit genuinely entangled states are robust. In particular, the generalized GHZ state remains nonlocal under arbitrary Wigner rotation and the generalized W state could admit local-hidden-variable models within a rather narrow range of parameters.