Theory Seminar: Witnessing quantum gravity in a lab

Anupam Mazumdar (Gröningen)
Is gravity classical or quantum? I will be discussing a protocol to precisely test the quantum aspect of gravity in a lab.

Anupam Mazumdar (Gröningen)
Herbert-Walther Lecture Hall G0.25
Wed, 11. September 2019, 11:30 am

Abstract:

Is gravity classical or quantum? I will be discussing a protocol to precisely test the quantum aspect of gravity in a lab. The proposal utilises the overarching physical property that local operations (supported by classical communication) cannot create entanglement between non-interacting systems. In the proposed experimental setting, two masses, each endowed with a spin-like degree of freedom, are made to gravitationally interact as they traverse adjacent interferometers. By ensuring that gravity is the sole agent acting between the masses, the observation of entanglement between the probes, would certify the quantum nature of gravity.Quite remarkably, the proposed scheme would provide a signature of quantumness of gravity that is within the grasp of state-of-the-art experiments, despite the purported weakness of the gravitational coupling. The manuscript shows that the challenges of avoiding non-Gravitational interactions (namely electromagnetic interactions of various forms) can be met, so that the quantum nature of gravity can be concluded without ambiguity, and through the sole, experimentally friendly test of entanglement between two spins.