Detecting single gravitons with gravitational wave detectors

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. In this talk, I will show that laboratory experiments can reveal signatures of single graviton exchange. I will outline how both interferometric and resonant-mass gravitational wave detectors can be adapted into single graviton detectors with future detector modifications. I will in particular focus on key details of how interferometric gravitational wave detectors can be adapted to graviton detectors [1]. Drawing a close analogy to the photoelectric effect, I will argue that such experiments may offer the first direct evidence for the quantum nature of gravity.

[1] H. A Louhglin, G. Tobar, E. Hall, and V. Sudhir “Wave-particle duality in the measurement of gravitational radiation,” Phys. Rev. Research 7, 043286 (2025).

general relativity and quantum cosmologyopticsquantum physics

Audience: advanced learners

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Tricontinental Quantum Fundamentals Seminar

Series comments: The Tricontinental Quantum Fundamentals Seminar (3C-QFS) is an online seminar series connecting researchers from Australia, Europe, and America. Our goal is to facilitate discussion between the three continents and bring together those working on foundational topics in relativistic quantum physics, covering but not limited to:

• Measurement, localisation, and causality in relativistic quantum theory
• Energy conditions and quantum inequalities
• Non-locality and observer-dependence of entanglement
• Quantum reference frames and symmetries in quantum theory
• Holography, AdS/CFT, and analogue gravity

For 3C-QFS, we wish to foster an inclusive community and promote open discussion by encouraging a casual atmosphere during the seminars.

The seminars are held online via Zoom, consisting of 40-60 minute talks followed by additional time for questions. We meet every three weeks on Tuesday, alternating between two times in order to connect research communities across two of the three continents.

For those unable to join the seminars live, talks are recorded and hosted on the 3C-QFS YouTube channel.

The seminar series is primarily for students and academics active in the foundations of physics. To sign up for the mailing list and join the seminars live, please complete the registration form on the 3C-QFS website.

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