Clocked Atom Delivery to a Photonic Crystal Waveguide

TL;DR

This study combines experiments and simulations to understand and control ultracold atomic motion near photonic crystal waveguides, enabling precise atomic delivery and potential applications in nonlinear optics.

Contribution

It introduces a quantitative framework for atomic trajectories near nanoscopic PCWs and demonstrates control of atomic flux using guided mode fields.

Findings

Validated numerical simulations with experimental data

Achieved ~50 nm spatial and 100 ns temporal resolution in atomic motion mapping

Demonstrated control of atomic trajectories using AC-Stark shifts

Abstract

Experiments and numerical simulations are described that develop quantitative understanding of atomic motion near the surfaces of nanoscopic photonic crystal waveguides (PCWs). Ultracold atoms are delivered from a moving optical lattice into the PCW. Synchronous with the moving lattice, transmission spectra for a guided-mode probe field are recorded as functions of lattice transport time and frequency detuning of the probe beam. By way of measurements such as these, we have been able to validate quantitatively our numerical simulations, which are based upon detailed understanding of atomic trajectories that pass around and through nanoscopic regions of the PCW under the influence of optical and surface forces. The resolution for mapping atomic motion is roughly 50 nm in space and 100 ns in time. By introducing auxiliary guided mode (GM) fields that provide spatially varying AC-Stark shifts, we have, to some degree, begun to control atomic trajectories, such as to enhance the flux into to the central vacuum gap of the PCW at predetermined times and with known AC-Stark shifts. Applications of these capabilities include enabling high fractional filling of optical trap sites within PCWs, calibration of optical fields within PCWs, and utilization of the time-dependent, optically dense atomic medium for novel nonlinear optical experiments.