  Searching for physics beyond the Standard Model is one of the main tasks of
experimental physics. Candidates for dark matter include axion-like ultralight
bosonic particles. Comagnetometers form ultra-high sensitivity probes for such
particles and any exotic field that interacts with the spin of an atom. Here,
we propose a multi-atom-species probe that enables not only to discover such
fields and measure their spectrum but also to determine the ratios of their
coupling strengths to sub-atomic elementary particles, electrons, neutrons and
protons. We further show that the multi-faceted capabilities of this probe may
be demonstrated with synthetic exotic fields generated by a combination of
regular magnetic fields and light-induced fictitious magnetic fields in alkali
atoms. These synthetic fields also enable the accurate calibration of any
magnetometer or comagnetometer probe for exotic physics.
