Phase-insensitive amplifier for quantum measurements

Precision measurement has been a primary driving force for advancing modern science. In particular, optical interferometers lead to the direct detection of gravitational waves from black holes and neutron stars, and can also be applied for axion dark matter detection. But how can we further improve optical measurements? The fundamental limit to their precision comes from the quantum nature of light. The canonical approach to overcoming the quantum limit is using the non-classical squeezed state of light. After decades of developments, it becomes full-fledged, but also reaches the hard limit from the optical loss that destroys the quantum decoherence. In this project, we will explore a new paradigm using quantum amplification that complements the squeezing technique and is robust against optical loss. The novelty involves an exploration of a phase-insensitive amplification process that leads to an asymmetrical amplification of the signal and the noise in optical interferometers. We will perform the first experimental study of an optomechanical amplifier and theoretically investigate the optimal amplification scheme. Our findings can lead to a new class of quantum techniques and will have a broad impact on high-precision detectors.