Measuring a single atom's position with extreme sub-wavelength resolution and force measurements in the yoctonewton range

TL;DR

This paper demonstrates ultra-precise measurement of a single atom's position and force at nanometer and yoctonewton scales using near-resonant radio frequency fields and magnetic gradients, advancing atomic-scale sensing capabilities.

Contribution

The study introduces a novel method for tracking a single atom's position with sub-nanometer accuracy and force sensitivity in the yoctonewton range, surpassing previous spatial and force measurement limits.

Findings

Position resolution of 0.12 nm achieved.

Force sensitivity of 2.2 × 10^{-23} N/√Hz demonstrated.

Real-time atom position tracking enabled.

Abstract

The center-of-mass position of a single trapped atomic ion is measured and tracked in time with high precision. Employing a near-resonant radio frequency field of wavelength 2.37 cm and a static magnetic field gradient of 19 T/m, the spatial location of the ion is determined with an unprecedented wavelength-relative resolution of 5 $\times$ 10$^{-9}$, corresponding to an absolute precision of 0.12 nm. Measurements of an electrostatic force on a single ion demonstrate a sensitivity of 2.2 $\times$ 10$^{-23} ~\text{N}/\sqrt{\text{Hz}}$. The real-time measurement of an atom's position complements the well-established technique of scanning near-field radio frequency transmission microscopy and opens up a novel route to using this method with path breaking spatial and force resolution.