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

ABSTRACT

Improved laboratory limits on the exotic spin- and velocity-dependent interaction at the micrometer scale are established with a single electron spin quantum sensor. The single electron spin of a near-surface nitrogen-vacancy center in diamond is used as the quantum sensor, and a fused-silica 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 sensed by the electron spin quantum sensor. Our experiment sets improved constraints on the exotic spin- and velocity-dependent interaction within the force range from 1.4 to 330 µm. The upper limit of the coupling g_{A}^{e}g_{V}^{N} at 200 µm is |g_{A}^{e}g_{V}^{N}|≤5.3×10^{-19}, significantly improving the current laboratory limit by more than 4 orders of magnitude.