Optical atomic clocks are the most accurate measurement devices ever constructed and
have found many applications in fundamental science and technology,–. The use of highly …

The last decade has seen unprecedented effort in dark matter model building at all mass
scales coupled with the design of numerous new detection strategies. Transformative …

Precision spectroscopy of atomic systems is an invaluable tool for the study of fundamental
interactions and symmetries. Recently, highly charged ions have been proposed to enable …

Inner-shell electrons naturally sense the electric field close to the nucleus, which can reach
extreme values beyond 1015 V cm− 1 for the innermost electrons. Especially in few-electron …

In Penning traps electromagnetic forces are used to confine charged particles under well-
controlled conditions for virtually unlimited time. Sensitive detection methods have been …

Efficient cooling of trapped charged particles is essential to many fundamental physics
experiments,, to high-precision metrology, and to quantum technology,. Until now …

Transition frequencies and fine-structure splittings of the 2 S 1 3→ 2 P 3 J transitions in
helium-like C 4+ 12 were measured by collinear laser spectroscopy on a 1-ppb level …

Abstract Comparison of precise predictions of the energy levels of the molecular hydrogen
ion H 2+—the simplest molecule—with measured vibrational transition frequencies would …

We present the measurements of individual bound electron g factors of Ne 20 9+ and Ne 22
9+ on the relative level of 0.1 parts per billion. The comparison with theory represents the …

Collinear laser spectroscopy has been performed on He-like C 4+ ions extracted from an
electron-beam ion source (EBIS). In order to determine the transition frequency with the …