Cold highly charged ions in a radio-frequency trap with superconducting magnetic shielding
Abstract
We implement sympathetic cooling of highly charged ions (HCI) by fully enclosing a linear Paul trap within a superconducting radio-frequency resonator. A quantization magnetic field applied while cooling down into the superconducting state remains present in the trap for centuries and external electromagnetic fluctuations are greatly suppressed. A magnetic field decay rate at the 10 s level is found using trapped Doppler-cooled Be ions as hyperfine-structure (hfs) qubits. Ramsey interferometry and spin-echo measurements on magnetically-sensitive hfs transitions yield coherence times of >400 ms, showing excellent passive shielding at frequencies down to DC. For sympathetic cooling of HCI, we extract them from an electron beam ion trap (EBIT) and co-crystallize one together with Doppler-cooled Be ions. By subsequently ejecting all but one Be ions, we prepare single HCI for quantum logic spectroscopy towards frequency metrology and qubit operations with a great variety of HCI species.
Keywords
Cite
@article{arxiv.2306.01670,
title = {Cold highly charged ions in a radio-frequency trap with superconducting magnetic shielding},
author = {Elwin A. Dijck and Christian Warnecke and Malte Wehrheim and Ruben B. Henninger and Julia Eff and Kostas Georgiou and Andrea Graf and Stepan Kokh and Lakshmi P. Kozhiparambil Sajith and Christopher Mayo and Vera M. Schäfer and Claudia Volk and Piet O. Schmidt and Thomas Pfeifer and José R. Crespo López-Urrutia},
journal= {arXiv preprint arXiv:2306.01670},
year = {2024}
}
Comments
16 pages, 19 figures. The following article has been submitted to Review of Scientific Instruments. After it is published, it will be found at https://rsi.aip.org/