2017/12/13 by Sougato Bose, Anupam Mazumdar, Gavin W. Morley +7 · 1 voice · 11 citations
Physics and Astronomy · #Quantum Mechanics and Applications #Mechanical and Optical Resonators #Quantum Electrodynamics and Casimir Effect
paper · pdf · doi:10.1103/physrevlett.119.240401
openalex publication_date 2017/12/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Understanding gravity in the framework of quantum mechanics is one of the great challenges in modern physics. However, the lack of empirical evidence has lead to a debate on whether gravity is a quantum entity. Despite varied proposed probes for quantum gravity, it is fair to say that there are no feasible ideas yet to test its quantum coherent behavior directly in a laboratory experiment. Here, we introduce an idea for such a test based on the principle that two objects cannot be entangled without a quantum mediator. We show that despite the weakness of gravity, the phase evolution induced by the gravitational interaction of two micron size test masses in adjacent matter-wave interferometers can detectably entangle them even when they are placed far apart enough to keep Casimir-Polder forces at bay. We provide a prescription for witnessing this entanglement, which certifies gravity as a quantum coherent mediator, through simple spin correlation measurements.