Constructing Local Models for General Measurements on Bosonic Gaussian States

Area of Science:

• Quantum Information Science
• Quantum Optics
• Foundations of Physics

Background:

• Quantum correlations challenge classical intuition and are central to quantum information.
• Gaussian quantum states are fundamental in quantum optics and information processing.
• Local hidden variable models attempt to explain quantum correlations classically.

Purpose of the Study:

• To establish a straightforward criterion for assessing the locality of correlations in Gaussian quantum states.
• To explore the relationship between entanglement and local hidden variable models in Gaussian systems.

Main Methods:

• Derivation of a sufficient criterion for the locality of correlations.
• Construction of a local hidden variable model that accounts for Gaussian noise.
• Application of the criterion to a two-mode squeezed state with displaced photodetection.

Main Results:

• A simple sufficient criterion for the locality of correlations from Gaussian states was derived.
• The proposed local hidden variable model effectively incorporates inherent Gaussian noise.
• The criterion demonstrated the existence of a local hidden variable model for entangled two-mode squeezed states within a specific parameter range.

Conclusions:

• The study provides a practical tool for analyzing quantum correlations in Gaussian states.
• It highlights that entanglement does not always preclude the existence of local hidden variable models.
• The findings contribute to understanding the boundary between quantum and classical correlations.