Towards a transportable aluminium ion quantum logic optical clock

authored by: Stephan Hannig, Lennart Pelzer, Nils Scharnhorst, Johannes Kramer, Mariia Stepanova, Zetian Xu, Nicolas Spethmann, Ian D. Leroux, Tanja E. Mehlstäubler, Piet Oliver Schmidt
Abstract: With the advent of optical clocks featuring fractional frequency uncertainties on the order of 10^-17 and below, new applications such as chronometric leveling with few-centimeter height resolution emerge. We are developing a transportable optical clock based on a single trapped aluminum ion, which is interrogated via quantum logic spectroscopy. We employ singly charged calcium as the logic ion for sympathetic cooling, state preparation, and readout. Here, we present a simple and compact physics and laser package for manipulation of ⁴⁰Ca⁺. Important features are a segmented multilayer trap with separate loading and probing zones, a compact titanium vacuum chamber, a near-diffraction-limited imaging system with high numerical aperture based on a single biaspheric lens, and an all-in-fiber ⁴⁰Ca⁺ repump laser system. We present preliminary estimates of the trap-induced frequency shifts on ²⁷Al⁺, derived from measurements with a single calcium ion. The micromotion-induced second-order Doppler shift for ²⁷Al⁺ has been determined to be δνEMMν=-0.4-0.3+0.4×10-18 and the black-body radiation shift is δν_BBR/ν = (-4.0 ± 0.4) × 10^-18. Moreover, heating rates of 30 (7) quanta per second at trap frequencies of ω_rad,Ca+ ≈ 2π × 2.5 MHz (ω_ax,Ca+ ≈ 2π × 1.5 MHz) in radial (axial) direction have been measured, enabling interrogation times of a few hundreds of milliseconds.
Organisation(s): Institute of Quantum Optics
CRC 1227 Designed Quantum States of Matter (DQ-mat)
External Organisation(s): Physikalisch-Technische Bundesanstalt PTB
Huazhong University of Science and Technology
Type: Article
Journal: Review of Scientific Instruments
Volume: 90
ISSN: 0034-6748
Publication date: 05.2019
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Instrumentation
Electronic version(s): https://doi.org/10.48550/arXiv.1901.02250 (Access: Open)
https://doi.org/10.1063/1.5090583 (Access: Open)
https://doi.org/10.15488/12800 (Access: Open)

BibTeX

@article{e2db471fe30d438ab899d1990fa81e53,
title = "Towards a transportable aluminium ion quantum logic optical clock",
abstract = "With the advent of optical clocks featuring fractional frequency uncertainties on the order of 10-17 and below, new applications such as chronometric leveling with few-centimeter height resolution emerge. We are developing a transportable optical clock based on a single trapped aluminum ion, which is interrogated via quantum logic spectroscopy. We employ singly charged calcium as the logic ion for sympathetic cooling, state preparation, and readout. Here, we present a simple and compact physics and laser package for manipulation of 40Ca+. Important features are a segmented multilayer trap with separate loading and probing zones, a compact titanium vacuum chamber, a near-diffraction-limited imaging system with high numerical aperture based on a single biaspheric lens, and an all-in-fiber 40Ca+ repump laser system. We present preliminary estimates of the trap-induced frequency shifts on 27Al+, derived from measurements with a single calcium ion. The micromotion-induced second-order Doppler shift for 27Al+ has been determined to be δνEMMν=-0.4-0.3+0.4×10-18 and the black-body radiation shift is δνBBR/ν = (-4.0 ± 0.4) × 10-18. Moreover, heating rates of 30 (7) quanta per second at trap frequencies of ωrad,Ca+ ≈ 2π × 2.5 MHz (ωax,Ca+ ≈ 2π × 1.5 MHz) in radial (axial) direction have been measured, enabling interrogation times of a few hundreds of milliseconds.",
author = "Stephan Hannig and Lennart Pelzer and Nils Scharnhorst and Johannes Kramer and Mariia Stepanova and Zetian Xu and Nicolas Spethmann and Leroux, {Ian D.} and Mehlst{\"a}ubler, {Tanja E.} and Schmidt, {Piet Oliver}",
note = "Funding information: We thank M. Dolezal and P. Balling from CMI for performing the thermography measurements of rf heated trap chips and S. A. King for stimulating discussion. We acknowledge support from PTB and DFG through CRC 1227 (DQ-mat), project B03 and CRC 1128 (geo-Q), and project A03. This project has received funding from the European Metrology Programme for Innovation and Research (EMPIR) co-financed by the participating states and from the European Union{\textquoteright}s Horizon 2020 research and innovation programme, Project No. 15SIB03 OC18. We acknowledge financial support by the Ministry of Science and Culture of Lower Saxony from “Nieders{\"a}chsisches Vorab” through “Fundamentals of Physics and Metrology (FPM)” initiative.",
year = "2019",
month = may,
doi = "10.48550/arXiv.1901.02250",
language = "English",
volume = "90",
journal = "Review of Scientific Instruments",
issn = "0034-6748",
publisher = "American Institute of Physics",
number = "5",
}