Lattice-induced photon scattering in an optical lattice clock

authored by: Sören Dörscher, Roman Schwarz, Ali Al-Masoudi, Stephan Falke, Uwe Sterr, Christian Lisdat
Abstract: We investigate scattering of lattice laser radiation in a strontium optical lattice clock and its implications for operating clocks at interrogation times up to several tens of seconds. Rayleigh scattering does not cause significant decoherence of the atomic superposition state near a magic wavelength. Among the Raman scattering processes, lattice-induced decay of the excited state (5s5p)P03 to the ground state (5s2)S01 via the state (5s5p)P13 is particularly relevant, as it reduces the effective lifetime of the excited state and gives rise to quantum projection noise in spectroscopy. We observe this process in our experiment and find a decay rate of 556(15)×10-6s-1 per photon recoil energy Er of effective lattice depth, which agrees well with the rate we predict from atomic data. We also derive a natural lifetime τ=330(140)s of the excited state P03 from our observations. Lattice-induced decay thus exceeds spontaneous decay at typical lattice depths used by present clocks. It eventually limits interrogation times in clocks restricted to high-intensity lattices but can be largely avoided, e.g., by operating them with shallow lattice potentials.
External Organisation(s): National Metrology Institute of Germany (PTB)
Toptica Photonics
Type: Article
Journal: Physical Review A
Volume: 97
ISSN: 2469-9926
Publication date: 25.06.2018
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Atomic and Molecular Physics, and Optics
Electronic version(s): https://doi.org/10.1103/PhysRevA.97.063419 (Access: Unknown)

BibTeX

@article{16d5211bd01f49a4b37a1b927cf76a4b,
title = "Lattice-induced photon scattering in an optical lattice clock",
abstract = "We investigate scattering of lattice laser radiation in a strontium optical lattice clock and its implications for operating clocks at interrogation times up to several tens of seconds. Rayleigh scattering does not cause significant decoherence of the atomic superposition state near a magic wavelength. Among the Raman scattering processes, lattice-induced decay of the excited state (5s5p)P03 to the ground state (5s2)S01 via the state (5s5p)P13 is particularly relevant, as it reduces the effective lifetime of the excited state and gives rise to quantum projection noise in spectroscopy. We observe this process in our experiment and find a decay rate of 556(15)×10-6s-1 per photon recoil energy Er of effective lattice depth, which agrees well with the rate we predict from atomic data. We also derive a natural lifetime τ=330(140)s of the excited state P03 from our observations. Lattice-induced decay thus exceeds spontaneous decay at typical lattice depths used by present clocks. It eventually limits interrogation times in clocks restricted to high-intensity lattices but can be largely avoided, e.g., by operating them with shallow lattice potentials.",
author = "S{\"o}ren D{\"o}rscher and Roman Schwarz and Ali Al-Masoudi and Stephan Falke and Uwe Sterr and Christian Lisdat",
note = "Funding information: This work is supported by QUEST, by DFG within CRC 1227 (DQ-mat, project B02) and RTG 1729. The results in this contribution partly come from the project EMPIR 15SIB03 OC18. This project has received funding from the EMPIR programme cofinanced by the Participating States and from the European Union's Horizon 2020 research and innovation programme.",
year = "2018",
month = jun,
day = "25",
doi = "10.1103/PhysRevA.97.063419",
language = "English",
volume = "97",
journal = "Physical Review A",
issn = "2469-9926",
publisher = "American Physical Society",
number = "6",
}