arXiv subjects

Q. Deplano

Publications and source records attributed to Q. Deplano.

3 recordsLinked to original sources

arXiv2026

Optical squeezing mediated by levitated oscillators at their quantum ground state

We demonstrate optical squeezing below the shot-noise level generated through the interaction of an optical cavity field with two center-of-mass modes of a levitated nanoparticle, simultaneously cooled to occupation numbers well below unity. By analyzing the quadrature fluctuations of the cavity output through heterodyne detection, we resolve the full spectral covariance matrix of the optical field and map regions of sub-shot-noise squeezing as a function of detection phase and frequency. Operating in the resolved sideband and strong coupling regime where mechanical modes hybridize with the optical mode, we observe consistent squeezing in the band 70-95 kHz with a lowest variance of 0.98 (2$\%$ below vacuum fluctuations). We thus demonstrate optical squeezing mediated by multiple mechanical oscillators in their quantum ground state, bridging mechanical quantum control with non-classical light and establishing levitated optomechanics as a platform for multimode quantum interactions.

quant-ph↗

arXiv2026

Stationary entanglement of a levitated oscillator with an optical field

Stationary entanglement between the motion of macroscopic objects and light is a long-standing goal of quantum optomechanics, with implications for both fundamental tests of quantum physics and emerging quantum technologies. We report the generation of quantum entanglement between the center-of-mass motion of a nanosphere levitated in an optical tweezer inside an optical cavity and the electromagnetic field. By heterodyne detection, we reconstruct the full set of optomechanical correlations and observe a violation of separability bounds between the mechanical motion and the quadratures of a propagating optical mode. This demonstrates the distribution of nonclassical correlations beyond the interaction region. The entanglement is generated at room temperature and remains robust over a broad range of parameters. Our results establish levitated optomechanical systems as a promising platform for continuous-variable quantum communication and for tests of macroscopic quantum physics.

quant-ph↗

arXiv2024

High purity two-dimensional levitated mechanical oscillator

In recent years, levitated optomechanics has delivered on the promise of reaching the motional quantum ground state. An important next milestone of the field would be the generation of mechanical entanglement. An ideal candidate is the two-dimensional motion in the polarization plane of an optical tweezer inside an optical cavity, where optical and mechanical modes are coupled via coherent scattering. Necessary conditions towards this achievement are two-dimensional ground state cooling along with substantial spectral overlap between the two modes. The latter condition is required to generate the necessary correlations, but unfortunately, it hinders efficient cooling thus narrowing the useful parameter space. In this work, we report the achievement of a high purity two-dimensional state in a regime where the strong optomechanical coupling induces the desired spectral superposition between oscillations in different directions, as reflected in the non-trivial spectral shape of the detected cavity field. As a result, significant correlations consistently arise between any pair of orthogonal directions, preventing the motion from being reduced to two independent one-dimensional oscillators and leading to higher purity compared to that scenario. Our system serves as an excellent platform for realizing continuous variable entanglement in two-dimensional motion.

quant-ph↗