Description:

The GQuEST (Gravity from the Quantum Entanglement of Space-Time) experiment uses tabletop-scale Michelson laser interferometers to probe for fluctuations in space-time. Our recently proposed interferometer design featuring a novel photon counting readout method provides unprecedented sensitivity, as it is not subject to the interferometric standard quantum limit. In this talk, I will give some theoretical background of recently proposed ‘geotropic’ quantum gravity models, go over the basics of laser interferometry and homodyne readout, and then go into detail on photon counting.  The accelerated accrual of statistical power 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.

Daniel Grass, PhD Student, Caltech

Host: Andrew Geraci