![]() | Date: Thursday 13th February 2025 Time: 1:00pm – 2:00pm AWST, 3:00pm-4:00pm AEST, 4:00pm-5:00pm AEDT Location: Online only. Please see your emails for more informaiton. |
Title: Detecting single gravitons with quantum-controlled mechanical resonators Bio: Germain is a PhD Student from Stockholm University, where he is working under the supervision of Dr. Magdalena Zych. Prior to this, Germain completed his Honours degree at the University of Queensland under the supervision of Professor Warwick Bowen on low energy tests of collapse models, before completing a MASt in theoretical physics at the University of Cambridge with the Cambridge Australia Scholarship and working as a research intern at the Okinawa Institute of Science and Technology. His research interests lie in the low energy interface of gravity and quantum mechanics, focusing on developing new proposals for testing quantum features of gravity, with his most recent work exploring the possibility for implementing a gravitational version of the photo-electric effect 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. Here we show that signatures of single gravitons 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 optomechanical read-out of single phonons of a multi-mode bar resonator. We analyse the feasibility of observing a signal from the inspiral, merger and post-merger phase of a compact binary inspiral. Our results show that single graviton signatures are within reach of experiments. In analogy to the discovery of the photoelectric effect for photons, such signatures can provide the first experimental evidence of the quantization of gravity. [1] G. Tobar, S. K. Manikandan, T. Beitel, and I. Pikovski, Nature Communications, 15 7229 (2024). [2] G. Tobar, Igor Pikovski, Michael E. Tobar, arXiv:2406.16898 (2024) |
The Australian Research Council Centre of Excellence for Engineered Quantum Systems (EQUS) acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to lands, waters and communities. We pay our respects to Aboriginal and Torres Strait Islander cultures and to Elders past and present.