Axion like particles multi-parameter sensing

Abstract

The search for the axion like particles (APLs)-one of the deepest puzzles in modern cosmology-may hold the key to understanding dark matter and dark energy. In this work, we introduce a setup taking advantage of the quantum metrology techniques to constrain the hypothetical mass and coupling constants of APLs by employing exotic pseudoscalar spin-spin interactions between fermions mediated by ALPs. A key advantage of our approach is the exploitation of position-dependent spin sensor results to the high sensitivity of the probe. To simultaneously investigate the axion mass and coupling constants, we invoke a multi-probe detection strategy. Through this strategy, we circumvent the singularity of the quantum Fisher information matrix as an ultimate upper bound on the sensitivity of any probe. For the axion masses in the range of $m_a {\le} 10^{-3} \text{eV}$, this setup can exclude values of axion coupling constants $g^e_pg^n_p$ down to $10^{-7}$.