New publication in Physical Review Letters Amplifying a zeptonewton force with a single ion

Nonlinear mechanical oscillators are ubiquitous in nature and widely used in technological applications. Driven nonlinear oscillators in the multistable regime are particularly interesting for applications such as force sensing, because small perturbations from a stable equilibrium can cause the oscillator to abruptly switch to other stable states.
In our recent work, we show that mechanical nonlinearity is readily obtained by confining a particle in a 3D funnel-shaped potential. The geometry-induced motional coupling introduces an intrinsic Duffing-type nonlinearity in the particle’s oscillation. Using a modified Paul trap, we realize such a potential for a single calcium ion. We observe bifurcation of the oscillator under strong driving and demonstrate the enhancement of a zeptonewton electrostatic force by a factor of 20.

Read the article at: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.153601