Quantum sensing with levitated optomechanical systems

Levitated optomechanics deals with controlling the mechanical motion of nanoscale objects in vacuum, resulting in highly isolated mechanical oscillators. Recent landmark experiments demonstrating quantum state preparation and interacting arrays of nanoparticles have established levitated optomechanics as a powerful platform with the potential to develop quantum sensors for technological and scientific applications, and are predicted to outperform other sensing platforms by several orders of magnitude.

The project seeks to address the question "how can we use quantum resources in optomechanical systems to achieve position measurement sensitivities below the standard quantum limit?".

In the first part of the project, we will build a table-top experimental setup that uses optical tweezers to trap nanoparticles in vacuum. The tweezer will be placed in an optical cavity, which will be used to cool the motion of the nanoparticle to the quantum ground state along multiple spatial dimensions.

In the second part, we will explore various quantum-enhanced sensing strategies to measure the displacement of the nanoparticle in response to external forces. In particular, we will make use of squeezed states of both the optical probe (tweezer) and the mechanical system (nanoparticle) to demonstrate sensitivities better than state-of-the-art sensors (10-9ms-2Hz-1/2).

This will pave the way towards testing fundamental physics (eg, searching for physics beyond the standard model) and developing commercial quantum sensors (eg, acceleration sensors for inertial navigation).