Sympathetically cooled highly charged ions in a radio-frequency trap with superconducting magnetic shielding

authored by: E. A. Dijck, Christian Warnecke, Malte Wehrheim, Ruben B. Henninger, Julia Eff, Kostas Georgiou, Andrea Graf, Stepan Kokh, Lakshmi P. Kozhiparambil Sajith, Christopher Mayo, Vera M. Schäfer, Claudia Volk, Piet O. Schmidt, Thomas Pfeifer, José R. Crespo López-Urrutia
Abstract: We sympathetically cool highly charged ions (HCI) in Coulomb crystals of Doppler-cooled Be⁺ ions confined in a cryogenic linear Paul trap that is integrated into a fully enclosing radio-frequency resonator manufactured from superconducting niobium. By preparing a single Be⁺ cooling ion and a single HCI, quantum logic spectroscopy toward frequency metrology and qubit operations with a great variety of species are enabled. While cooling down the assembly through its transition temperature into the superconducting state, an applied quantization magnetic field becomes persistent, and the trap becomes shielded from subsequent external electromagnetic fluctuations. Using a magnetically sensitive hyperfine transition of Be⁺ as a qubit, we measure the fractional decay rate of the stored magnetic field to be at the 10⁻¹⁰ s⁻¹ level. Ramsey interferometry and spin-echo measurements yield coherence times of >400 ms, demonstrating excellent passive magnetic shielding at frequencies down to DC.
Organisation(s): Institute of Quantum Optics
External Organisation(s): Max Planck Institute for Nuclear Physics
Heidelberg University
National Metrology Institute of Germany (PTB)
University of Birmingham
Humboldt-Universität zu Berlin
Deutsches Elektronen-Synchrotron (DESY)
Type: Article
Journal: Review of scientific instruments
Volume: 94
ISSN: 0034-6748
Publication date: 08.2023
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Instrumentation
Electronic version(s): https://doi.org/10.1063/5.0160537 (Access: Open)

BibTeX

@article{eb0f0c6158774a18bf54d5e9425a5636,
title = "Sympathetically cooled highly charged ions in a radio-frequency trap with superconducting magnetic shielding",
abstract = "We sympathetically cool highly charged ions (HCI) in Coulomb crystals of Doppler-cooled Be+ ions confined in a cryogenic linear Paul trap that is integrated into a fully enclosing radio-frequency resonator manufactured from superconducting niobium. By preparing a single Be+ cooling ion and a single HCI, quantum logic spectroscopy toward frequency metrology and qubit operations with a great variety of species are enabled. While cooling down the assembly through its transition temperature into the superconducting state, an applied quantization magnetic field becomes persistent, and the trap becomes shielded from subsequent external electromagnetic fluctuations. Using a magnetically sensitive hyperfine transition of Be+ as a qubit, we measure the fractional decay rate of the stored magnetic field to be at the 10−10 s−1 level. Ramsey interferometry and spin-echo measurements yield coherence times of >400 ms, demonstrating excellent passive magnetic shielding at frequencies down to DC.",
author = "Dijck, {E. A.} and Christian Warnecke and Malte Wehrheim and Henninger, {Ruben B.} and Julia Eff and Kostas Georgiou and Andrea Graf and Stepan Kokh and {Kozhiparambil Sajith}, {Lakshmi P.} and Christopher Mayo and Sch{\"a}fer, {Vera M.} and Claudia Volk and Schmidt, {Piet O.} and Thomas Pfeifer and {Crespo L{\'o}pez-Urrutia}, {Jos{\'e} R.}",
note = "Funding Information: We acknowledge the MPIK workshops with T. Spranz and his team for the outstanding quality of their work in manufacturing hardware for the experiment and the engineering design group of F. M{\"u}ller for their excellent support. We acknowledge S. Schiller and S. Sturm for providing access to reference signals from a maser and GPS clock. We acknowledge our collaborators at the Physikalisch-Technische Bundesanstalt for providing us with a bi-aspheric lens and laser components. This project received funding from the Max Planck Society; the Max-Planck–Riken–PTB-Center for Time, Constants and Fundamental Symmetries; the European Metrology Program for Innovation and Research (EMPIR), which is co-financed by the Participating States and from the European Union{\textquoteright}s Horizon 2020 research and innovation program (Project Nos. 17FUN07 CC4C and 20FUN01 TSCAC); the European Research Council (ERC) under the European Union{\textquoteright}s Horizon 2020 research and innovation program (Grant Agreement No. 101019987); and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) through the collaborative research center Grant No. SFB 1225 ISOQUANT, through Germany{\textquoteright}s Excellence Strategy Grant No. EXC-2123 QuantumFrontiers–390837967, and through Grant No. SCHM2678/5-1. We acknowledge the generous funding by the German Federal Ministry of Education and Research (BMBF) within the program Grant No. 13N15973 “Quantum technologies—from basic research to market” (Projekt VAUQSI—Viel-Frequenz-Ansteuerung Ultrastabiler Qubits in Supraleitenden Ionenfallen). ",
year = "2023",
month = aug,
doi = "10.1063/5.0160537",
language = "English",
volume = "94",
journal = "Review of scientific instruments",
issn = "0034-6748",
publisher = "American Institute of Physics",
number = "8",
}