Suppressing Recoil Heating in Levitated Optomechanics using Squeezed Light

We theoretically show that laser recoil heating in free-space levitated optomechanics can be strongly reduced by shining squeezed light onto an optically trapped nanoparticle. The presence of squeezing modifies the quantum electrodynamical light-matter interaction in a way that enables us to control the amount of information that the scattered light carries about a given mechanical degree of freedom. We analyze the trade-off between measurement imprecision and back-action noise and show that optical detection beyond the standard quantum limit can be achieved. We predict that, with state-of-the-art squeezed light sources, laser recoil heating reduction of at least $60\%$ can be attained by squeezing a single Gaussian mode with an appropriate incidence direction. Our results, which are valid both for motional and librational degrees of freedom, will lead to improved feedback cooling schemes as well as boost the coherence time of optically levitated nanoparticles in the quantum regime