Trapped-ion quantum sensors have become highly sensitive tools for the search of physics beyond the Standard Model. Recently, stringent tests of local Lorentz-invariance (LLI) have been conducted with precision spectroscopy in trapped ions. We here elaborate on robust radio-frequency composite-pulse...

After more than three years of postdoctoral research in our group, Laura has moved back to Amsterdam to start as an Assistant Professor at the Vrije Universiteit (VU) Amsterdam. In Amsterdam, Laura will develop her research line in precision quantum metrology with trapped ions for tests of...

Lars worked in our joint SFB project A07 with Luis Santos on the dynamics of Coulomb crystals and investigated phase transitions and energy transport with topological defects from classical to quantum. After many nice joint publications between our groups, Lars upgrades himself now to Dr. Lars...

In this work we propose to use Hermite-Gaussian (HG) modes in photonic integrated circuits (PICs) for precision spectroscopy of dipole-forbidden atomic-clock transitions such as the octupole (E3) transition of the Yb-173 ion.

In this paper we describe our bichromatic UV detection system for atomically-resolved imaging of ions, which is part of our In+ multi-ion clock.

Kai C. Grensemann received his master’s degree. We congratulate him on this achievement!

His work paved the way for the test of local Lorentz invariance with a multi-ion Coulomb crystal to further enhance the sensitivity. His investigation on the rf composite pulse sequence and the field gradient...

In this paper we apply quench cooling to a single Ytterbium ion. We study the optimal parameters for fast and deep cooling in the sideband, intermediate and semi-classical cooling regime which can be flexibly tuned via the quench laser intensity. Moreover, we discuss the non-thermal distribution of...

Giving a throughout overview on the experimental setup of the multi-ion indium clock, her thesis serves as a good reference for new members of our team and the scientific community interested in optical clocks. Finishing her Ph.D. studies was a and also a personal achievement. Congratulations!

In attempts to unify all fundamental forces in a single quantum consistent theory it has been suggested that Lorentz symmetry is violated. We have investigated the principle of local Lorentz invariance in a single trapped Yb⁺ ion by comparing spatially oriented atomic orbitals. The highly...

Moritz von Boehn receives his master's degree. We congratulate him on this achievement!

The title of his thesis is

Modelling of sympathetic Doppler cooling and analysis of probe field induced ac-Stark shifts in an ¹¹⁵In⁺ optical clock

You can find the thesis here.