Photon Counting Interferometry to Detect Geontropic Space-Time Fluctuations with GQuEST

• DOI: 10.48550/arxiv.2404.07524
• Publication Date: 2025-02-14
• Authors: Sander M. Vermeulen; Torrey Cullen; Daniel Grass; Ian A. O. MacMillan; Alexander J. Ramirez; Jeffrey Wack; Boris Korzh; Vincent S. H. Lee; Kathryn M. Zurek; Chris Stoughton; Lee McCuller
• Keywords: Quantum Physics; Physics - Instrumentation and Detectors; Physics; QC1-999; FOS: Physical sciences; General Relativity and Quantum Cosmology (gr-qc); Instrumentation and Detectors (physics.ins-det); Astrophysics - Instrumentation and Methods for Astrophysics; Quantum Physics (quant-ph); Instrumentation and Methods for Astrophysics (astro-ph.IM); General Relativity and Quantum Cosmology

The gravity from the quantum entanglement of space-time (GQuEST) experiment uses tabletop-scale Michelson laser interferometers to probe for fluctuations in space-time. We present a practicable interferometer design featuring a novel photon-counting readout method that provides unprecedented sensitivity, as it is not subject to the interferometric standard quantum limit. We evaluate the potential of this design to measure space-time fluctuations motivated by recent “geontropic” quantum gravity models. The accelerated accrual of Fisher information offered by the photon-counting readout enables GQuEST to detect the predicted quantum gravity phenomena within measurement times at least 100 times shorter than equivalent conventional interferometers. The GQuEST design, thus, enables a fast and sensitive search for signatures of quantum gravity in a laboratory-scale experiment. Published by the American Physical Society 2025