arXiv subjects

Nadine Meyer

Publications and source records attributed to Nadine Meyer.

15 recordsLinked to original sources

arXiv2026

3D trapping of a meta-atom in an intensity minimum

High-refractive-index particles have recently attracted a growing interest in optical levitation experiments, offering the ability to further engineer optical forces through electromagnetic Mie resonances. Unlike standard silica particles, which are predominantly trapped in the dipole regime and exhibit trap frequencies mainly determined by material density, resonant meta-atoms formed by high-index particles enable qualitatively new trapping behaviors. In this work, we experimentally investigate the trapping of resonant silicon particles in an optical standing wave. A direct comparison of silicon and silica highlights the fundamental differences in their optical force scaling and trapping dynamics. Beyond conventional trapping at intensity-maxima, we demonstrate deterministic and stable three-dimensional trapping of silicon nanoparticles in optical intensity minima, a regime that remains inaccessible for silica particles. Drawing a mesoscopic analogy with blue-detuned atom trapping, our results establish meta-atoms as a versatile approach to further extend the optical manipulation tool box towards accessing novel trapping regimes e.g. in close proximity to a surface.

physics.optics↗

arXiv2025

Cooling of an optically levitated nanoparticle via measurement-free coherent feedback

We demonstrate coherent, measurement-free optical feedback control of a levitated nanoparticle, achieving phonon occupations down to a few hundred phonons. Unlike measurement-based feedback, this all-optical scheme preserves the correlations between mechanical motion and the feedback signal. Adjustment of the feedback phase and delay provides precise and tunable control over the system dynamics. The ultimate cooling performance is currently limited by phase noise, which we analyze within a theoretical framework that outlines the constraints and prospects for reaching the motional ground state. Our results establish coherent feedback as a powerful tool for quantum control of levitated systems, extending beyond center-of-mass cooling.

quant-ph↗

arXiv2025

Accelerated State Expansion of a Nanoparticle in a Dark Inverted Potential

While the wave packet of a massive particle grows linearly under free dynamics, it grows exponentially in an inverted harmonic potential, offering a pathway to rapidly increase quantum fluctuations to macroscopic dimensions. In this work, we experimentally demonstrate this principle by expanding the center-of-mass thermal state of a 125nm silica nanoparticle to a position uncertainty of 43.4nm within 260 $μ$s. This expansion, achieved using an inverted dark potential to minimize decoherence from photon recoil, represents a 952-fold increase, reaching a scale comparable to the nanoparticle's physical size. This work represents a key advancement toward preparing macroscopic quantum superpositions at unprecedented mass and length scales.

quant-ph↗

arXiv2025

Controlling the sign of optical forces using metaoptics

Precise manipulation of small objects using light holds transformative potential across diverse fields. While research in optical trapping and manipulation predominantly relies on the attraction of solid matter to light intensity maxima, here we demonstrate that meta-optics enables a departure from this accepted behavior. Specifically, we present deterministic control over the sign of optical forces exerted on a metasurface integrated on a suspended silicon nanomembrane. By tailoring the geometry of the constituent meta-atoms, we engineer the coherent superposition of their multipolar modes, and consequently, the net optical force experienced by the metasurface within a phase-controlled optical standing wave. In excellent agreement with 3D numerical simulations, we experimentally realize both attractive and repulsive forces on distinct metasurface designs, directly mirroring the behavior of two-level systems interacting with optical fields. This work establishes a versatile platform for the optical control of nanoscale mechanical systems, opening new avenues for both fundamental research and engineering.

physics.optics↗

arXiv2023

Vacuum levitation and motion control on chip

Levitation in vacuum has evolved into a versatile technique which has already benefited diverse scientific directions, from force sensing and thermodynamics to material science and chemistry. It also holds great promises of advancing the study of quantum mechanics in the unexplored macroscopic regime. While most current levitation platforms are complex and bulky, miniaturization is sought to gain robustness and facilitate their integration into confined settings, such as cryostats or portable devices. Integration on chip is also anticipated to enhance the control over the particle motion through a more precise engineering of optical and electric fields. As a substantial milestone towards this goal, we present here levitation and motion control in high vacuum of a silica nanoparticle at the surface of a hybrid optical-electrostatic chip. By combining fiber-based optical trapping and sensitive position detection with cold damping through planar electrodes, we cool the particle motion to a few hundred phonons. Our results pave the way to the next generation of integrated levitation platforms combining integrated photonics and nanophotonics with engineered electric potentials, towards complex state preparation and read out.

physics.optics↗

arXiv2023

Levitated Optomechanics with Meta-Atoms

We propose to introduce additional control in levitated optomechanics by trapping a meta-atom, i.e. a subwavelength and high-permittivity dielectric particle supporting Mie resonances. In particular, we theoretically demonstrate that optical levitation and center-of-mass ground-state cooling of silicon nanoparticles in vacuum is not only experimentally feasible but it offers enhanced performance over widely used silica particles, in terms of both trap frequency and trap depth. Moreover, we show that, by adjusting the detuning of the trapping laser with respect to the particle's resonance, the sign of the polarizability becomes negative, enabling levitation in the minimum of laser intensity e.g. at the nodes of a standing wave. The latter opens the door to trapping nanoparticles in the optical near-field combining red and blue-detuned frequencies, in analogy to two-level atoms, which is of interest for generating strong coupling to photonic nanostructures and short-distance force sensing.

physics.optics↗

arXiv2022

Ultra-thin Tunable Optomechanical Metalens

Reconfigurable metasurfaces offer great promises to enhance photonics technology by combining integration with improved functionalities. Recently, reconfigurability in otherwise static metasurfaces has been achieved by modifying the electric permittivity of the meta-atoms themselves or their immediate surrounding. Yet, it remains challenging to achieve significant and fast tunability without increasing bulkiness. Here, we demonstrate an ultra-thin tunable metalens whose focal distance can be changed through optomechanical control with moderate continuous wave intensities. We achieve fast focal length changes of more than 5% with response time of the order of 10$μ$s

physics.optics↗

arXiv2022

Simultaneous ground-state cooling of two mechanical modes of a levitated nanoparticle

The quantum ground state of a massive mechanical system is a steppingstone for investigating macroscopic quantum states and building high fidelity sensors. With the recent achievement of ground-state cooling of a single motional mode, levitated nanoparticles have entered the quantum domain. To overcome detrimental cross-coupling and decoherence effects, quantum control needs to be expanded to more system dimensions, but the effect of a decoupled dark mode has thus far hindered cavity-based ground state cooling of multiple mechanical modes. Here, we demonstrate two-dimensional (2D) ground-state cooling of an optically levitated nanoparticle. Utilising coherent scattering into an optical cavity mode, we reduce the occupation numbers of two separate centre-of-mass modes to 0.83 and 0.81, respectively. By controlling the frequency separation and the cavity coupling strengths of the nanoparticle's mechanical modes, we show the transition from 1D to 2D ground-state cooling while avoiding the effect of dark modes. Our results lay the foundations for generating quantum-limited high orbital angular momentum states with applications in rotation sensing. The demonstrated 2D control, combined with already shown capabilities of ground-state cooling along the third motional axis, opens the door for full 3D ground-state cooling of a massive object.

quant-ph↗

arXiv2022

Mechanical squeezing via unstable dynamics in a microcavity

We theoretically show that strong mechanical quantum squeezing in a linear optomechanical system can be rapidly generated through the dynamical instability reached in the far red-detuned and ultrastrong coupling regime. We show that this mechanism, which harnesses unstable multimode quantum dynamics, is particularly suited to levitated optomechanics, and we argue for its feasibility for the case of a levitated nanoparticle coupled to a microcavity via coherent scattering. We predict that for sub-millimeter-sized cavities the particle motion, initially thermal and well above its ground state, becomes mechanically squeezed by tens of decibels on a microsecond timescale. Our results bring forth optical microcavities in the unresolved sideband regime as powerful mechanical squeezers for levitated nanoparticles, and hence as key tools for quantum-enhanced inertial and force sensing.

quant-ph↗

arXiv2022

A chemical nano-reactor based on a levitated nanoparticle in vacuum

A single levitated nanoparticle is used as a nano-reactor for studying surface chemistry at the nanoscale. Optical levitation under controlled pressure, surrounding gas composition, and humidity provides extreme control over the nanoparticle, including dynamics, charge, and surface chemistry. Using a single nanoparticle avoids ensemble averages and allows to study how the presence of silanol groups at its surface affects the adsorption and desorption of water from the background gas with unprecedented real time, spatial, and temporal resolution. Here, we demonstrate the unique potential of this versatile platform by studying the Zhuravlev model in silica particles. In contrast to standard methods, our system allowed the first observation of an abrupt and irreversible change in scattering cross section, mass, and mechanical eigenfrequency during the dehydroxylation process, indicating changes in density, refractive index and volume.

physics.chem-ph↗

arXiv2021

Precision calibration of the Duffing oscillator with phase control

The Duffing oscillator is a nonlinear extension of the ubiquitous harmonic oscillator and as such plays an outstanding role in science and technology. Experimentally, the system parameters are determined by a measurement of its response to an external excitation. When changing the amplitude or frequency of the external excitation, a sudden jump in the response function reveals the nonlinear dynamics prominently. However, this bistability leaves part of the full response function unobserved, which limits the precise measurement of the system parameters. Here, we exploit the often unknown fact that the response of a Duffing oscillator with nonlinear damping is a unique function of its phase. By actively stabilizing the oscillator's phase we map out the full response function. This phase control allows us to precisely determine the system parameters. Our results are particularly important for characterizing nanoscale resonators, where nonlinear effects are observed readily and which hold great promise for next generation of ultrasensitive force and mass measurements. We demonstrate our approach experimentally with an optically levitated particle in high vacuum.

physics.app-ph↗

arXiv2021

Strong Optomechanical Coupling at Room Temperature by Coherent Scattering

Quantum control of a system requires the manipulation of quantum states faster than any decoherence rate. For mesoscopic systems, this has so far only been reached by few cryogenic systems. An important milestone towards quantum control is the so-called strong coupling regime, which in cavity optomechanics corresponds to an optomechanical coupling strength larger than cavity decay rate and mechanical damping. Here, we demonstrate the strong coupling regime at room temperature between a levitated silica particle and a high finesse optical cavity. Normal mode splitting is achieved by employing coherent scattering, instead of directly driving the cavity. The coupling strength achieved here approaches three times the cavity linewidth, crossing deep into the strong coupling regime. Entering the strong coupling regime is an essential step towards quantum control with mesoscopic objects at room temperature.

quant-ph↗

arXiv2019

Resolved Sideband Cooling of a Levitated Nanoparticle in the Presence of Laser Phase Noise

We investigate the influence of laser phase noise heating on resolved sideband cooling in the context of cooling the center-of-mass motion of a levitated nanoparticle in a high-finesse cavity. Although phase noise heating is not a fundamental physical constraint, the regime where it becomes the main limitation in Levitodynamics has so far been unexplored and hence embodies from this point forward the main obstacle in reaching the motional ground state of levitated mesoscopic objects with resolved sideband cooling. We reach minimal center-of-mass temperatures comparable to $T_{min}=10$mK at a pressure of $p = 3\times 10^{-7}$mbar, solely limited by phase noise. Finally we present possible strategies towards motional ground state cooling in the presence of phase noise.

quant-ph↗

arXiv2019

Optimal Feedback Cooling of a Charged Levitated Nanoparticle with Adaptive Control

We use an optimal control protocol to cool one mode of the center of mass motion of an optically levitated nanoparticle. The feedback technique relies on exerting a Coulomb force on a charged particle with a pair of electrodes and follows the control law of a linear quadratic regulator, whose gains are optimized by a machine learning algorithm in under 5 s. With a simpler and more robust setup than optical feedback schemes, we achieve a minimum center of mass temperature of 5 mK at $3\times 10^{-7}$ mbar and transients 10 to 600 times faster than cold damping. This cooling technique can be easily extended to 3D cooling and is particularly relevant for studies demanding high repetition rates and force sensing experiments with levitated objects.

physics.ins-det↗

arXiv2017

Observation of Stable Jones-Roberts Solitons in Bose-Einstein Condensates

We experimentally generate two-dimensional Jones-Roberts solitons in a three-dimensional atomic Bose-Einstein condensate by imprinting a triangular phase pattern. By monitoring their dynamics we observe that this kind of solitary waves are resistant to both dynamic (snaking) and thermodynamic instabilities, that usually are known to strongly limit the lifetime of dark plane solitons in dimensions higher than one. We additionally find signatures of a possible dipole-like interaction between them. Our results confirm that Jones-Roberts solitons are stable solutions of the non-linear Schrödinger equation in higher dimensions and promote these excitations for applications beyond matter wave physics, like energy and information transport in noisy and inhomogeneous environments.

cond-mat.quant-gas↗