Field-Tunable Meissner-Levitated Ferromagnetic Microsphere Sensor for Cryogenic Casimir and Short-Range Gravity Tests

• URL: http://arxiv.org/abs/2602.13829v1
• Date: Sat, 14 Feb 2026 15:47:15 GMT
• Title: Field-Tunable Meissner-Levitated Ferromagnetic Microsphere Sensor for Cryogenic Casimir and Short-Range Gravity Tests
• Authors: Yi-Chong Ren, Feng Xu, Wijnand Broer, Xiao-Jing Chen, Fei Xue,
• Abstract summary: Near-field force measurements at submicron separations can probe Casimir effects and hypothetical short-range interactions.<n>We propose a quantum force-gradient sensor in which a ferromagnetic microsphere is Meissner-levitated above a type-I superconducting plane.<n>We quantify the trade-off between suppression of electrostatic patch potentials and eddy-current dissipation, project force sensitivities of $sim 10-19,fluxrmN,Hz-1/2$ at millikelvin temperatures.
• Score: 17.02406347252292
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Near-field force measurements at submicron separations can probe Casimir effects and hypothetical short-range interactions, but require cryogenic operation and stable, \textit{in situ} control of separation-dependent backgrounds. We propose a self-calibrating quantum force-gradient sensor in which a ferromagnetic microsphere is Meissner-levitated above a type-I superconducting plane, while a bias magnetic field reproducibly tunes the equilibrium gap for in situ separation scans without mechanical approach. The force gradient is encoded as a resonance-frequency shift tracked by a phase-locked loop, and the motion is read out with a SQUID-coupled, flux-tunable microwave resonator that provides adjustable measurement strength without optical heating. Using the input--output formalism, we derive the conditions for reaching the standard quantum limit (SQL) and identify a counterintuitive scaling law: because displacement-to-flux transduction increases with microsphere size, larger microspheres require fewer photons to reach the SQL, enabling a pathway to macroscopic quantum metrology. We quantify the trade-off between suppression of electrostatic patch potentials (via Au coating) and eddy-current dissipation, project force sensitivities of $\sim 10^{-19}\,\rm{N\,Hz^{-1/2}}$ at millikelvin temperatures, and outline protocols to extract Casimir pressure and constrain Yukawa-type deviations from Newtonian gravity over $0.1$--$10\,μ\mathrm{m}$.

Related papers

• Quantum Hall Effect at 0.002T [46.680073344221626]
  We demonstrate a significant reduction in external inhomogeneity using a double-layer graphene architecture separated by an ultra-thin hexagonal boron nitride layer.<n>Shubnikov de-Haas oscillations emerge at magnetic fields below 1 mT, while integer quantum Hall features are observed at 0.002T.<n>These results demonstrate the platform's suitability for investigating strongly correlated electronic phases in graphene-based heterostructures.
  arXiv  Detail & Related papers  (2026-01-22T14:40:33Z)
• Robust AC vector sensing at zero magnetic field with pentacene [45.7221176995052]
  Quantum sensors based on electronic spins have emerged as powerful probes of microwave-frequency fields.<n>Here, we demonstrate microwave vector magnetometry using the photoexcited spin triplet of pentacene molecules.
  arXiv  Detail & Related papers  (2025-12-06T03:49:12Z)
• Experimental Proposal on Scalable Radio-Frequency Magnetometer with Trapped Ions [8.315103872142915]
  We propose a scalable trapped-ion magnetometer utilizing the mixed dynamical decoupling method.<n>We demonstrate that a sensitivity of 13 $rmfT/sqrtrmHz$ for the radio-frequency field could be reached.
  arXiv  Detail & Related papers  (2025-10-26T03:47:25Z)
• Exploring molecular supersolidity via exact and mean-field theories: single microwave shielding [0.0]
  We develop an extended Gross-Pitaevskii framework for bosonic molecules under single microwave shielding.<n>We benchmark it against exact Quantum Monte Carlo simulations.<n>We show that elliptic microwave polarization induces direction-dependent superfluidity--absent in cylindrically symmetric systems.
  arXiv  Detail & Related papers  (2025-09-22T17:25:39Z)
• Diamagnetic micro-chip traps for levitated nanoparticle entanglement experiments [0.0]
  Quantum Gravity Mediated Entanglement (QGEM) protocol offers a novel method to probe the quantumness of gravitational interactions at non-relativistic scales. We propose using magnetic traps based on micro-fabricated wires to trap nanoparticles for interferometric entanglement experiments.
  arXiv  Detail & Related papers  (2024-11-04T17:48:32Z)
• In-situ-tunable spin-spin interactions in a Penning trap with in-bore optomechanics [41.94295877935867]
  We present an optomechanical system for in-situ tuning of the coherent spin-motion and spin-spin interaction strength. We characterize the system using measurements of the induced mean-field spin precession. These experiments show approximately a $times2$ variation in the ratio of the coherent to incoherent interaction strength.
  arXiv  Detail & Related papers  (2024-01-31T11:00:39Z)
• Thermal masses and trapped-ion quantum spin models: a self-consistent approach to Yukawa-type interactions in the $λ\!φ^4$ model [44.99833362998488]
  A quantum simulation of magnetism in trapped-ion systems makes use of the crystal vibrations to mediate pairwise interactions between spins. These interactions can be accounted for by a long-wavelength relativistic theory, where the phonons are described by a coarse-grained Klein-Gordon field. We show that thermal effects, which can be controlled by laser cooling, can unveil this flow through the appearance of thermal masses in interacting QFTs.
  arXiv  Detail & Related papers  (2023-05-10T12:59:07Z)
• A background-free optically levitated charge sensor [50.591267188664666]
  We introduce a new technique to model and eliminate dipole moment interactions limiting the performance of sensors employing levitated objects. As a demonstration, this is applied to the search for unknown charges of a magnitude much below that of an electron. As a by-product of the technique, the electromagnetic properties of the levitated objects can also be measured on an individual basis.
  arXiv  Detail & Related papers  (2021-12-20T08:16:28Z)
• Continuous-Wave Frequency Upconversion with a Molecular Optomechanical Nanocavity [46.43254474406406]
  We use molecular cavity optomechanics to demonstrate upconversion of sub-microwatt continuous-wave signals at $sim$32THz into the visible domain at ambient conditions. The device consists in a plasmonic nanocavity hosting a small number of molecules. The incoming field resonantly drives a collective molecular vibration, which imprints an optomechanical modulation on a visible pump laser.
  arXiv  Detail & Related papers  (2021-07-07T06:23:14Z)
• Single-quadrature quantum magnetometry in cavity electromagnonics [0.0]
  Scheme of ultra-sensitive magnetometer in the cavity quantum electromagnonics is proposed. Intracavity microwave mode coupled to a magnonic mode via magnetic dipole interaction is proposed. The estimated theoretical sensitivity of the proposed magnetic amplifier-sensor is approximately in the order of $10-18T/sqrtHz$ which is competitive compared to the current state-of-the-art magnetometers.
  arXiv  Detail & Related papers  (2020-11-11T21:23:19Z)
• Ultralow mechanical damping with Meissner-levitated ferromagnetic microparticles [0.0]
  We show experimentally that micromagnets levitated above type-I superconductors feature very low damping at low frequency and low temperature. Our results open the way towards the development of ultrasensitive magnetomechanical sensors with potential applications to magnetometry and gravimetry.
  arXiv  Detail & Related papers  (2019-12-27T17:30:04Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.