Lamb-Dicke spectroscopy of atoms in a hollow-core photonic crystal fibre

• DOI: 10.1038/ncomms5096
• Publication Date: 2014-06-17T11:57:03Z
• Authors: Shoichi Okaba; Tetsushi Takano; Fetah Benabid; Tom Bradley; Luca Vincetti; Zakhar Maizelis; Valery Yampol'skii; Franco Nori; Hidetoshi Katori
• Keywords: Atomic Physics (physics.atom-ph); 0103 physical sciences; [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic; FOS: Physical sciences; Photonic crystal fibers; Optical lattice clock; Quantum metrology; 01 natural sciences; Article; Physics - Atomic Physics

31 pages, 8 figures<br/>Unlike photons, which are conveniently handled by mirrors and optical fibres without loss of coherence, atoms lose their coherence via atom-atom and atom-wall interactions. This decoherence of atoms deteriorates the performance of atomic clocks and magnetometers, and also hinders their miniaturisation. Here we report a novel platform for precision spectroscopy. Ultracold strontium atoms inside a kKagome-lattice hollow-core photonic crystal fibre (HC-PCF) are transversely confined by an optical lattice to prevent atoms from interacting with the fibre wall. By confining at most one atom in each lattice site, to avoid atom-atom interactions and Doppler effect, a 7.8-kHz-wide spectrum is observed for the $^1 S_0-{}^3P_1$ (m=0) transition. Atoms singly trapped in a magic lattice in hollow-core photonic crystal fibresHC-PCFs improve the optical depth while preserving atomic coherence time.<br/>