Improved Limits on an Exotic Spin- and Velocity-Dependent Interaction at the Micrometer Scale with an Ensemble-NV-Diamond Magnetometer

TL;DR

This study uses an ensemble-NV-diamond magnetometer to set new, more stringent limits on exotic spin- and velocity-dependent interactions at micrometer scales, advancing the search for particles beyond the standard model.

Contribution

The paper demonstrates the application of an ensemble-NV-diamond magnetometer to improve constraints on exotic interactions at micrometer distances, showcasing its potential for new particle searches.

Findings

Established new bounds for the coupling parameter $f_ot$ from 5 to 400 μm.

Achieved an upper limit of |f_ot| ≤ 1.1×10^{-11} at 100 μm, three orders of magnitude better than previous constraints.

Validated NV ensemble magnetometry as a promising platform for beyond-standard-model particle searches.

Abstract

Searching for exotic interactions provides a path for exploring new particles beyond the standard model. Here, we used an ensemble-NV-diamond magnetometer to search for an exotic spin- and velocity-dependent interaction between polarized electron spins and unpolarized nucleons at the micrometer scale. A thin layer of nitrogen-vacancy electronic spin ensemble in diamond is utilized as both the solid-state spin quantum sensor and the polarized electron source, and a vibrating lead sphere serves as the moving unpolarized nucleon source. The exotic interaction is searched by detecting the possible effective magnetic field induced by the moving unpolarized nucleon source using the ensemble-NV-diamond magnetometer. Our result establishes new bounds for the coupling parameter $f_\perp$ within the force range from 5 to 400 $\rm \mu$m. The upper limit of the coupling parameter at 100 $\rm \mu$m is $\lvert f_\perp \rvert \leq 1.1\times 10^{-11}$, which is 3 orders of magnitude more stringent than the previous constraint. This result shows that NV ensemble can be a promising platform to search for hypothetical particles beyond the standard model.