Trapped and laser-cooled ions allow for a high degree of control of atomic quantum systems. They are the basis for modern atomic clocks, quantum computers and quantum simulators. In our research we use ion Coulomb crystals, i.e. many-body systems with complex dynamics, for precision spectroscopy. This paves the way to novel optical ion frequency standards with ultra-high stability and accuracy...
In the latest adjustment of fundamental constants [1], spectroscopy of ro-vibrational transitions in the molecular hydrogen ion HD$^+$ contributed for the first time to the determination of particle masses, in particular the proton-electron mass ratio $m_p/m_e$, the precision of which was improved by a factor of 3.5. It was also used to constrain hypothetical beyond-standard-model interactions...
Optical tweezers offer new opportunities to control and manipulate trapped ions with applications in quantum information processing, metrology and precision spectroscopy. The tweezers may be used to modify the local confinement of the ions, thereby modifying the soundwave spectrum of the entire crystal. In this way, the soundwave mediated spin-spin interactions between the ions may be...
