Discover weak signals with quantum-optomechanical sensors and hypothesis testing

• Applicant: Marta Maria Marchese, Ph.D.
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 510053905

The main goal of the proposed project is to address fundamental questions in quantum physics, concerning the detection and characterization of weak unknown forces. I propose a methodology to improve the potential of optomechanical systems as platforms for the sensing of weak forces. Optomechanical systems usually consist of a mechanical resonator whose motion can be controlled by external quantum laser fields, and it is affected by the new force. My approach combines quantum metrology with hypothesis testing tools. This results in two main advantages: it provides strategies to enhance the sensitivity of optomechanical sensors and it allows for making claims on the nature of the detected signal. I will apply the methodology to investigate three promising avenues towards new physics, namely collapse models, dark matter detection, quantum-gravity signatures. But thanks to the general formulation, other fundamental forces could be tested with the proposed protocol as well. The first step consists in identifying and characterizing the effect of the signal of interest on the sensor to distinguish it from other noises signals. I will further employ quantum metrology tools to explore how different state preparation and measurement settings affect the sensitivity. Quantum features of resources and measurements are expected to lead to an enhancement of the sensitivity. I will develop a protocol of hypothesis testing to investigate the nature of the weak unknown signal, i.e., when few data are available and there are many unconstrained parameters. Parameter estimation tools will allow to narrow down the space of parameters and ultimately to rule out some of the theoretical models. Finally, I will conceive and propose optimized setups for an experimental implementation. To sum up, this proposed project establishes a novel statistical framework to investigate weak unknown forces and it paves the way for the systematic experimental discovery (or falsification) of new fundamental physics.

• DFG Programme: WBP Position