Sensing Atomic Motion from the Zero Point to Room Temperature with Ultrafast Atom Interferometry
K. G. Johnson, Brian Neyenhuis, Jonathan Mizrahi +2 more
We sense the motion of a trapped atomic ion using a sequence of state-dependent ultrafast momentum kicks. We use this atom interferometer to characterize a nearly pure quantum state with n=1 phonon and accurately measure thermal states ranging from near the zero-point energy to n[over ¯]~10^{4}, with the possibility of extending at least 100 times higher in energy. The complete energy range of this method spans from the ground state to far outside of the Lamb-Dicke regime, where atomic motion is greater than the optical wavelength. Apart from thermometry, these interferometric techniques are useful for characterizing ultrafast entangling gates between multiple trapped ions.
arXiv:1507.06591•Physical Review Letters•Nov 16, 2015•33 citations