Extreme-ultraviolet frequency combs for precision metrology and attosecond science

I Pupeza, C Zhang, M Högner, J Ye - Nature Photonics, 2021‏ - nature.com
Femtosecond mode-locked lasers producing visible/infrared frequency combs have steadily
advanced our understanding of fundamental processes in nature. For example, optical …

Narrow and ultranarrow transitions in highly charged Xe ions as probes of fifth forces

NH Rehbehn, MK Rosner, JC Berengut, PO Schmidt… - Physical Review Letters, 2023‏ - APS
Optical frequency metrology in atoms and ions can probe hypothetical fifth forces between
electrons and neutrons by sensing minute perturbations of the electronic wave function …

Inner-shell clock transition in atomic thulium with a small blackbody radiation shift

A Golovizin, E Fedorova, D Tregubov… - Nature …, 2019‏ - nature.com
One of the key systematic effects limiting the performance of state-of-the-art optical clocks is
the blackbody radiation (BBR) shift. Here, we demonstrate unusually low sensitivity of a 1.14 …

[HTML][HTML] The Heidelberg compact electron beam ion traps

P Micke, S Kühn, L Buchauer, JR Harries… - Review of Scientific …, 2018‏ - pubs.aip.org
Electron beam ion traps (EBITs) are ideal tools for both production and study of highly
charged ions (HCIs). In order to reduce their construction, maintenance, and operation costs …

Detection of metastable electronic states by Penning trap mass spectrometry

RX Schüssler, H Bekker, M Braß, H Cakir… - Nature, 2020‏ - nature.com
State-of-the-art optical clocks achieve precisions of 10− 18 or better using ensembles of
atoms in optical lattices, or individual ions in radio-frequency traps,. Promising candidates …

[HTML][HTML] Closed-cycle, low-vibration 4 K cryostat for ion traps and other applications

P Micke, J Stark, SA King, T Leopold, T Pfeifer… - Review of Scientific …, 2019‏ - pubs.aip.org
In vacuo cryogenic environments are ideal for applications requiring both low temperatures
and extremely low particle densities. This enables reaching long storage and coherence …

XUV frequency comb production with an astigmatism-compensated enhancement cavity

J Nauta, JH Oelmann, A Borodin, A Ackermann… - Optics express, 2021‏ - opg.optica.org
We have developed an extreme ultraviolet (XUV) frequency comb for performing ultra-high
precision spectroscopy on the many XUV transitions found in highly charged ions (HCI) …

Atom interferometer driven by a picosecond frequency comb

C Solaro, C Debavelaere, P Cladé… - Physical Review Letters, 2022‏ - APS
We demonstrate a light-pulse atom interferometer based on the diffraction of free-falling
atoms by a picosecond frequency-comb laser. More specifically, we coherently split and …

Below-threshold harmonic generation in gas-jets for Th-229 nuclear spectroscopy

A Schönberg, HS Salman, A Tajalli, S Kumar, I Hartl… - Optics express, 2023‏ - opg.optica.org
The generation of below-threshold harmonics in gas-jets constitutes a promising path
towards optical frequency combs in the vacuum ultra-violet (VUV) spectral range. Of …

[HTML][HTML] An ultralow-noise superconducting radio-frequency ion trap for frequency metrology with highly charged ions

J Stark, C Warnecke, S Bogen, S Chen… - Review of Scientific …, 2021‏ - pubs.aip.org
We present a novel ultrastable superconducting radio-frequency (RF) ion trap realized as a
combination of an RF cavity and a linear Paul trap. Its RF quadrupole mode at 34.52 MHz …