A tool for measuring atomic properties at the quantum limit

Performing high-resolution, high-sensitivity measurements of light and matter at the quantum limit requires extraordinary tools. Due to the difficulties of manipulating atoms with the necessary control, such measurements are often made by manipulating light. The measurement of atoms at this level of precision, however, is of much interest for applications such as atomic clocks, atomic spectroscopy and atom interferometry.

Hidetoshi Katori from the RIKEN Quantum Metrology Laboratory and Franco Nori from the RIKEN Center for Emergent Matter Science, in collaboration with co-workers from the University of Tokyo and a number of international institutions, have now developed a method to confine atoms in an 'optical lattice' formed inside a hollow-core optical fiber.

The researchers used a hollow-core optical fiber with a structure known as a kagome lattice—a honeycomb-like structure that supports a periodic optical 'potential' (Fig. 1). Atoms passing down the central channel of the hollow-core fiber are confined within the periodicity of this three-dimensional optical lattice. This confinement keeps the atoms isolated and protected from unwanted collisions with other atoms or the walls of the fiber, factors that have degraded the performance of similar approaches in the past. The optical lattice elegantly overcomes these problems and produces a minimally perturbed, optically dense atomic sample with improved regularity or 'coherence'.