Coherent interaction of atoms with a beam of light confined in a light cage

JULIAN GARGIULO; FLAVIE DAVIDSON-MARQUIS; ESTEBAN GOMEZ-LOPEZ; BUMJOON JANG; TIM KROH; CHRIS MUELLER; MARIO ZIEGLER; STEFAN A. MAIER; HARALD KUEBLER; MARKUS A. SCHMIDT; OLIVER BENSON

Light: science & applications

Nature Portfolio

Año: 2021 vol. 10

2095-5545

Controlling coherent interaction between optical fields and quantum systems in scalable, integrated platforms isessential for quantum technologies. Miniaturised, warm alkali-vapour cells integrated with on-chip photonic devicesrepresent an attractive system, in particular for delay or storage of a single-photon quantum state. Hollow-core fibresor planar waveguides are widely used to confine light over long distances enhancing light-matter interaction inatomic-vapour cells. However, they suffer from inefficient filling times, enhanced dephasing for atoms near thesurfaces, and limited light-matter overlap. We report here on the observation of modified electromagnetically inducedtransparency for a non-diffractive beam of light in an on-chip, laterally-accessible hollow-core light cage. Atomic layerdeposition of an alumina nanofilm onto the light-cage structure was utilised to precisely tune the high-transmissionspectral region of the light-cage mode to the operation wavelength of the atomic transition, while additionallyprotecting the polymer against the corrosive alkali vapour. The experiments show strong, coherent light-mattercoupling over lengths substantially exceeding the Rayleigh range. Additionally, the stable non-degrading performanceand extreme versatility of the light cage provide an excellent basis for a manifold of quantum-storage and quantumnonlinear applications, highlighting it as a compelling candidate for all-on-chip, integrable, low-cost, vapour-basedphoton delay.