Journal Article 1 Mention
Detecting single gravitons with quantum sensing
Germain Tobar•2024
Sreenath K. ManikandanThomas Beitel
Top 1% · 99th Percentile
60 citations · Atomic and Molecular Physics, and Optics
Open AccessAxions: From Heaven to EarthQUANTUM INFORMATION ENCODING AND DECODING FOR QUANTUM SENSINGCAREER: Towards Low-Energy Tests of Quantum Gravity with AMO SystemsQuantum optics at the interface with gravity

Summary

1 Sample Definition And Size

The study investigates the interaction between gravitational waves and massive quantum acoustic resonators (bar resonators) cooled to their quantum ground state. It is a theoretical analysis; no human or animal subjects are involved, and no sample size in terms of participants is applicable.

2 Study Type

The work is a theoretical study proposing a detection scheme, involving analytical derivations and feasibility estimates; it is not an experimental study but a theoretical proposal.

3 Conflicts Of Interest

No conflicts of interest are declared in the article; acknowledgements list funding sources but no competing interests are stated.

4 Results Summary

Key findings include derivation of spontaneous and stimulated single-graviton absorption/emission rates. Spontaneous emission rates are extremely low (e.g., ~10^{-40} Hz for atomic transitions) and thus unobservable. However, stimulated absorption rates can be significant: for an aluminum bar of mass ~1800 kg and gravitational wave amplitude h ≈ 5×10^{-22}, the stimulated transition rate Γ_stim ≈ 1 Hz. For a neutron star merger like GW170817, a beryllium resonator of mass ~15 kg at ~100 Hz could detect single gravitons. At higher frequencies (e.g., 5.5 MHz, h₀ ~10^{-16}), a resonator mass as low as ~10 g could suffice. The proposal relies on continuous quantum sensing of energy eigenstates and correlation with classical LIGO detections to identify single graviton absorption events.

Abstract

The quantization of gravity is widely believed to result in gravitons - particles of discrete energy that form gravitational waves. But their detection has so far been considered impossible. Here we show that signatures of single graviton exchange can be observed in laboratory experiments. We show that stimulated and spontaneous single-graviton processes can become relevant for massive quantum acoustic resonators and that stimulated absorption can be resolved through continuous sensing of quantum jumps. We analyze the feasibility of observing the exchange of single energy quanta between matter and gravitational waves. Our results show that single graviton signatures are within reach of experiments. In analogy to the discovery of the photo-electric effect for photons, such signatures can provide the first experimental clue of the quantization of gravity.

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