Searching spin-mass interaction using a diamagnetic levitated magnetic-resonance force sensor

Axion-like particles (ALPs) are predicted to mediate exotic interactions between spin and mass. We propose an ALP-searching experiment based on the levitated micro-mechanical oscillator, which is one of the most sensitive sensors for spin-mass forces at a short distance. The experiment tests the spin-mass resonant interaction between the polarized electron spins and a diamagnetically levitated microsphere. By periodically flipping the electron spins, the contamination from non-resonant background forces can be eliminated. The levitated micro-oscillator can prospectively enhance the sensitivity by nearly 3 orders over current experiments for ALPs with mass of 7 meV.