Robust Bell Nonlocality from Gottesman-Kitaev-Preskill States

• URL: http://arxiv.org/abs/2601.16189v1
• Date: Thu, 22 Jan 2026 18:41:13 GMT
• Title: Robust Bell Nonlocality from Gottesman-Kitaev-Preskill States
• Authors: Xiaotian Yang, Santiago Zamora, Rafael Chaves, Ulrik L. Andersen, Jonatan Bohr Brask, A. de Oliveira Junior,
• Abstract summary: Bell tests based on homodyne detection are strongly constrained in continuous-variable systems.<n>We consider a physically motivated model in which each party performs homodyne detection and digitizes the continuous outcome.<n>We show that finitely squeezed GKP-encoded GHZ and W states nevertheless exhibit strong multipartite nonlocality.
• Score: 0.36944296923226316
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Bell tests based on homodyne detection are strongly constrained in continuous-variable systems. Can Gottesman-Kitaev-Preskill (GKP) encoding turn homodyne detection into a practical tool for revealing Bell nonlocality? We consider a physically motivated model in which each party performs homodyne detection and digitizes the continuous outcome via a fixed periodic binning, corresponding to logical Pauli measurements. Within this framework, we derive a bipartite no-go: CHSH cannot be violated for Bell-pair states. Moving beyond two parties, we show that finitely squeezed GKP-encoded GHZ and W states nevertheless exhibit strong multipartite nonlocality, violating multipartite Bell inequalities with homodyne-only readout. We quantify the required squeezing thresholds and robustness to loss, providing a route toward homodyne-based Bell tests in continuous-variable systems.

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