Description
The GQuEST experiment uses tabletop-scale Michelson laser interferometers to probe for fluctuations in space-time. We present a new experimental technique, called photon counting interferometry’, which yields sensitivity beyond the interferometric standard quantum limit. We will implement this technique to search for individual photons produced by hypotheticalgeontropic’ space-time fluctuations, as proposed by Verlinde & Zurek. Our photon-counting readout design uses optical cavities to filter out quantum shot noise, a noise source that limits gravitational-wave detectors such as LIGO. Photon-counting readout fundamentally outperforms quantum squeezing, and is the optimal quantum metrology scheme to measure stochastic signals, such as space-time fluctuations. The GQuEST experiment thus enables a practicable search for signatures of quantum gravity in a laboratory-scale experiment.
