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arXiv:2512.19358

Talking with a ghost: semi-virtual coupled levitated oscillators

Ronghao Yin, Yugang Ren, Deok Young Seo, Anoushka Sinha, Jonathan D. Pritchett, Qiongyuan Wu, James Millen

physics.ins-detquant-phSubmitted Dec 22, 2025• Announced Dec 23, 2025
v1 · Dec 22, 2025v2 · Jan 27, 2026
arXivHTMLPDF

Abstract

Mesoscopic particles levitated by optical, electrical or magnetic fields act as mechanical oscillators with a range of surprising properties, such as tuneable oscillation frequencies, access to rotational motion, and remarkable quality factors. Coupled levitated particles display rich dynamics and non-reciprocal interactions, with applications in sensing and the exploration of non-equilibrium and quantum physics. In this work, we present a single levitated particle displaying coupled-oscillator dynamics by generating an interaction with a virtual or ``ghost'' particle. This ghost levitated particle is simulated on an analogue computer, and hence its prperties can be dynamically varied. Our work represents a new angle on measurement-based bath engineering and physical simulation, and in the future could lead to the generation of novel cooling mechanisms and complex physical simulation.

Journal reference
Photonics 2026, 13(2), 117
DOI
10.3390/photonics13020117
Comments
16 pages, 7 figures, Comments are welcome!

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Manipulating the motion of macroscopic objects near their quantum mechanical uncertainties has been desired in diverse fields, including fundamental physics, sensing, and transducers. Despite progress in ground-state cooling of a levitated solid particle, realizing its nonclassical states has been elusive. Here, we demonstrate quantum squeezing of the motion of a single nanoparticle by rapidly varying its oscillation frequency. We reveal appreciable narrowing of the velocity variance to -4.9 ± 0.1 decibels of that of the ground state using free-expansion measurements. Our work shows that a levitated nanoparticle offers an ideal platform for studying nonclassical states of its motion and provides a route to developing applications in quantum sensing and exploring quantum mechanics at a macroscopic scale.
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Nonlinearities in multimode mechanical systems can give rise to rich dynamical phenomena with great potential for sensing applications and for future quantum experiments. We demonstrate that the coupled center-of-mass and rotational motion of a Meissner-levitated micromagnet offer a promising platform for nonlinear dynamics, combining low dissipation, magnetic tunability, strong intrinsic Duffing nonlinearities, and nonlinear intermodal couplings. We use this tunability to demonstrate the generation of a mechanical frequency comb in the micromagnet dynamics, realized by parametric excitation of two translational modes followed by cascaded nonlinear frequency mixing, which produces a phononic comb with tunable spacing. At large amplitudes, nonlinear coupling to a low-frequency librational mode of the magnet leads to parametric excitation and phase locking of that mode, generating a dense spectral fine structure at subharmonics of the drive. These results establish levitated micromagnets as a platform for nonlinear multimode mechanics, with potential applications in precision sensing and quantum-limited metrology.