Gravitationally Induced Entanglement between Two Massive Particles is Sufficient Evidence of Quantum Effects in Gravity.

By C. Marletto, Vlatko Vedral. Physical Review Letters, 2017

651 citations recorded by the source corpus.

All existing quantum-gravity proposals are extremely hard to test in practice. Quantum effects in the gravitational field are exceptionally small, unlike those in the electromagnetic field. The fundamental reason is that the gravitational coupling constant is about 43 orders of magnitude smaller than the fine structure constant, which governs light-matter interactions. For example, detecting gravitons-the hypothetical quanta of the gravitational field predicted by certain quantum-gravity proposals-is deemed to be practically impossible. Here we adopt a radically different, quantum-information-theoretic approach to testing quantum gravity. We propose witnessing quantumlike features in the gravitational field, by probing it with two masses each in a superposition of two locations. First, we prove that any system (e.g., a field) mediating entanglement between two quantum systems must be quantum. This argument is general and does not rely on any specific dynamics. Then, we propose an experiment to detect the entanglement generated between two masses via gravitational interaction. By our argument, the degree of entanglement between the masses is a witness of the field quantization. This experiment does not require any quantum control over gravity. It is also closer to realization than detecting gravitons or detecting quantum gravitational vacuum fluctuations.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Physiology

View Paper: https://www.semanticscholar.org/paper/cc3ce675814bf734aeed67ffd0c58c5732a664db

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In Astronomy and Astrophysics

In Atomic and Molecular Physics, and Optics

Citations in the corpus

On the possibility of laboratory evidence for quantum superposition of geometries (2018, background): “As emphasized in [2, 5], a general argument based on information theory demands that a physical entity can entangle two systems only if it is itself described by quantum (non-commuting) variables, therefore detection of the BMV effect counts as evidence that gravity is quantised (see also [6, 7].”