Surpassing the Energy Resolution Limit with ferromagnetic torque sensors

Abstract

We discuss the fundamental noise limitations of a ferromagnetic torque sensor based on a levitated magnet in the tipping regime. We evaluate the optimal magnetic field resolution taking into account the thermomechanical noise and the mechanical detection noise at the standard quantum limit (SQL). We find that the Energy Resolution Limit (ERL), pointed out in recent literature as a relevant benchmark for most classes of magnetometers, can be surpassed by many orders of magnitude. Moreover, similarly to the case of a ferromagnetic gyroscope, it is also possible to surpass the standard quantum limit for magnetometry with independent spins, arising from spin-projection noise. Our finding indicates that magnetomechanical systems optimized for magnetometry can achieve a magnetic field resolution per unit volume several orders of magnitude better than any conventional magnetometer. We discuss possible implications, focusing on fundamental physics problems such as the search for exotic interactions beyond the standard model.

arXiv comment6 pages, 3 figures

References in corpus (14)

• Magnetic sensitivity beyond the projection noise limit by spin squeezing
• High-Resolution Magnetometry with a Spinor Bose-Einstein Condensate
• Optomechanical sensing of spontaneous wave-function collapse
• Quantum limits to the energy resolution of magnetic field sensors
• Single-Spin Magnetomechanics with Levitated Micromagnets
• Acceleration sensing with magnetically levitated oscillators above a superconductor
• Ultralow mechanical damping with Meissner-levitated ferromagnetic microparticles
• A Precessing Ferromagnetic Needle Magnetometer
• Quantum Spin Stabilized Magnetic Levitation
• Dynamics of a Ferromagnetic Particle Levitated Over a Superconductor
• Gravity Probe Spin: Prospects for measuring general-relativistic precession of intrinsic spin using a ferromagnetic gyroscope
• Ferromagnetic Gyroscopes for Tests of Fundamental Physics
• Multi-second magnetic coherence in a single domain spinor Bose-Einstein condensate
• Scale-invariant spin dynamics and the quantum limits of field sensing

Cited by in corpus (9)

• Challenging theories of dark energy with levitated force sensor
• Constraints on Spin-Spin-Velocity-Dependent Interaction
• Spin-dependent exotic interactions
• Ultralight dark matter detection with levitated ferromagnets
• Quantum thermodynamic derivation of the energy resolution limit in magnetometry
• Microscopic theory of a precessing ferromagnet for ultrasensitive magnetometry
• Levitated Milligram-scale Ferromagnetic Magnetometer at Room Temperature
• Torque-free manipulation of nanoparticle rotations via embedded spins
• Modeling frequency instability in high-quality resonant experiments