  We propose a quantum sensing scheme for measuring weak forces based on a
symmetry-breaking adiabatic transition in the quantum Rabi model. We show that
the system described by the Rabi Hamiltonian can serve as a sensor for
extremely weak forces with sensitivity beyond the yN $/\sqrt{\text{Hz}}$ range.
We propose an implementation of this sensing protocol using a single trapped
ion. A major advantage of our scheme is that the force detection is performed
by projective measurement of the population of the spin states at the end of
the transition, instead of the far slower phonon number measurement used
hitherto.
