Optimal Fidelity Witnesses for Gravitational Entanglement

Abstract

Optomechanical systems open new possibilities in fundamental research at the interface between quantum information and gravity. Recently, an ambitious experimental proposal was suggested by Bose et al. to measure the entanglement between two optomechanical systems generated by their gravitational interaction. The scheme relies on witnessing entanglement between the two systems. Here we develop a general framework to study the quality of bipartite entanglement witnesses using fidelity witnesses. We then apply this framework to the gravitational entanglement proposal, optimizing for the detection of entanglement. We construct a witness consisting of only 5 non-trivial spin measurements, which we compare with other proposed witnesses. With post-processing our witness can detect entanglement for any choice of phases in the setup, up to a set of measure zero.

10 pages, 5 figures

References in corpus (12)

• Entanglement detection
• A Spin Entanglement Witness for Quantum Gravity
• Gravitationally-induced entanglement between two massive particles is sufficient evidence of quantum effects in gravity
• Efficient quantum state tomography
• Creating and Verifying a Quantum Superposition in a Micro-optomechanical System
• Using an atom interferometer to infer gravitational entanglement generation
• Decoherence effects in non-classicality tests of gravity
• Witnessing the non-classical nature of gravity in the presence of unknown interactions
• Qudits for Witnessing Quantum Gravity Induced Entanglement of Masses Under Decoherence
• Enhanced force sensitivity and entanglement in periodically driven optomechanics
• On the Significance of Interferometric Revivals for the Fundamental Description of Gravity
• Limits on inference of gravitational entanglement

Cited by in corpus (5)

• Massive quantum systems as interfaces of quantum mechanics and gravity
• On inference of quantization from gravitationally induced entanglement
• Gravitational Harmonium: Gravitationally Induced Entanglement in a Harmonic Trap
• The generation rate of quantum gravity induced entanglement with multiple massive particles
• Benchmarks for quantum communication via gravity