Experimental Constraint on an Exotic Parity-Odd Spin- and Velocity-Dependent Interaction with a Single Electron Spin Quantum Sensor

Abstract: n improved laboratory bound on the exotic spin- and velocity-dependent interaction at micrometer scale is established with a single electron spin quantum sensor. The single electron spin of a near-surface nitrogen-vacancy center in diamond is utilized as the quantum sensor and a vibrating half-sphere lens is taken as the source of the moving nucleons. The exotic interaction between the polarized electron and the moving nucleon source is explored by measuring the possible magnetic field felt by the electron spin quantum sensor. Our experiment set improved constraints on the exotic spin- and velocity-dependent interaction within the force range from 1 to 330 $\mu$m. The upper limit of the coupling $g_A^eg_V^N $ at $200 ~\mu m$ is $| g_A^e g_V^N| \leq 8.0\times10^{-19}$, significantly improving the current laboratory limit by more than four orders of magnitude.