title: Lamb-Dicke spectroscopy of atoms in a hollow-core photonic crystal fibre.
abstract: 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 miniaturization. Here we report a novel platform for precision spectroscopy. Ultracold strontium atoms inside a kagome-lattice hollow-core photonic crystal fibre 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)S0-(3)P1(m=0) transition. Atoms singly trapped in a magic lattice in hollow-core photonic crystal fibres improve the optical depth while preserving atomic coherence time.
authors.affiliation: 1] Department of Applied Physics, Graduate School of Engineering, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo 113-8656, Japan [2] Innovative Space-Time Project, ERATO, Japan Science and Technology Agency, 7-3-1 Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Shoichi
authors.initials: S
authors.lastname: Okaba
authors.affiliation: 1] Department of Applied Physics, Graduate School of Engineering, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo 113-8656, Japan [2] Innovative Space-Time Project, ERATO, Japan Science and Technology Agency, 7-3-1 Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Takano
authors.affiliation: 1] GPPMM group, Xlim Research Institute, CNRS UMR7252, 123, Albert Thomas, Limoges 87060, France [2] Physics department, University of Bath, Claverton Down, Bath BA2 7AY, UK.
authors.forename: Fetah
authors.initials: F
authors.lastname: Benabid
authors.affiliation: 1] GPPMM group, Xlim Research Institute, CNRS UMR7252, 123, Albert Thomas, Limoges 87060, France [2] Physics department, University of Bath, Claverton Down, Bath BA2 7AY, UK.
authors.forename: Tom
authors.initials: T
authors.lastname: Bradley
authors.affiliation: 1] GPPMM group, Xlim Research Institute, CNRS UMR7252, 123, Albert Thomas, Limoges 87060, France [2] Department of Engineering "Enzo Ferrari", University of Modena and Reggio Emilia, Modena I-41125, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Vincetti
authors.affiliation: 1] A.Ya. Usikov Institute for Radiophysics and Electronics, National Academy of Science of Ukraine, 12 Acad. Proskura Str., Kharkov 61085, Ukraine [2] V.N. Karazin Kharkov National University, 4 Pl. Svobody, Kharkov 61077, Ukraine.
authors.forename: Zakhar
authors.initials: Z
authors.lastname: Maizelis
authors.affiliation: 1] A.Ya. Usikov Institute for Radiophysics and Electronics, National Academy of Science of Ukraine, 12 Acad. Proskura Str., Kharkov 61085, Ukraine [2] V.N. Karazin Kharkov National University, 4 Pl. Svobody, Kharkov 61077, Ukraine.
authors.forename: Valery
authors.initials: V
authors.lastname: Yampol'skii
authors.affiliation: 1] CEMS, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan [2] Physics Department, University of Michigan, Ann Arbor, Michigan 48109-1120, USA.
authors.forename: Franco
authors.initials: F
authors.lastname: Nori
authors.affiliation: 1] Department of Applied Physics, Graduate School of Engineering, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo 113-8656, Japan [2] Innovative Space-Time Project, ERATO, Japan Science and Technology Agency, 7-3-1 Bunkyo-ku, Tokyo 113-8656, Japan [3] Quantum Metrology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan [4] RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Katori