Related Experiment Video
Updated: Dec 22, 2025

High-Speed Magnetic Tweezers for Nanomechanical Measurements on Force-Sensitive Elements
Published on: May 12, 2023
Constraints on the Velocity and Spin Dependent Exotic Interaction at the Micrometer Range
Jihua Ding1, Jianbo Wang1, Xue Zhou2
1MOE Key Laboratory of Fundamental Quantities Measurement, Hubei Key Laboratory of Gravitation and Quantum Physics, School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.
Abstract:
We report on an experimental test of the velocity and spin dependent exotic interaction that can be mediated by new light bosons. The interaction is searched by measuring the force between a gold sphere and a microfabricated magnetic structure using a cantilever. The magnetic structure consists of stripes with antiparallel electron spin polarization so that the exotic interaction between the polarized electrons in the magnetic structure and the unpolarized nucleons in the gold sphere varies periodically, which helps to suppress the spurious background signals. The experiment sets the strongest laboratory constraints on the coupling constant between electrons and nucleons at the micrometer range with f_{⊥}<5.3×10^{-8} at λ=5 μm.
Related Concept Videos
Spin–Spin Coupling Constant: Overview
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Spin–Spin Coupling: One-Bond Coupling
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
Atomic Nuclei: Nuclear Spin State Population Distribution
Atomic Nuclei: Nuclear Spin State Overview

