Max Planck-RIKEN-PTB Center for

Advanced ion traps and ion manipulation techniques

Involved senior scientists and institutions in alphabetical order:
K. Blaum, J. R. Crespo , T. Mehlstäubler, A. Mooser , C. Ospelkaus , T. Pfeifer, P. Schmidt, C. Smorra , S. Sturm , T. Udem, S. Ulmer – MPIK, MPQ, PTB, RIKEN

Classical Penning-trap spectroscopy is approaching towards reaching parts per trillion limits, then limited by manufacturing uncertainties, magnetic field stability, and particle-trap interaction. To overcome these levels of precision, novel trap designs, detectors at higher sensitivity, faster measurement cycles and advanced magnetic shielding systems will be required. In the line of the general improvement of the performance of Penning-trap experiments or ion trap experiments in general, it is planned to implement 7-electrode Penning traps, double magnetic bottle traps, and three-dimensional selfshielding coil-systems. Implementation of advanced quantum logic techniques in Penning traps require novel trap geometries and optical access for lasers and fluorescence detection. Coupling of atomic ions to protons is facilitated by small and microfabricated trap geometries because the coupling rate scales as the inverse third power of the distance. Motional control over atomic ions in Penning traps combined with high coupling rates will enable full control over motional states at the single quantum level of single (anti-)protons, enabling deterministic motional state initialization. To achieve these goals, micro-structured Penning trap arrays, motional state preserving transport techniques and stimulated-Raman laser sources for spin-motional couplings in Penning traps will be jointly developed. Ultimately, it may be possible to bring entanglement-enhanced metrology to the realm of subatomic particles.
High-resolution spectroscopy in Paul traps has reached estimated inaccuracies of a few parts in 10^-18 for a single ion. However, to realize such a resolution in a frequency comparison within a reasonable averaging time, multiple ions need to be probed. This demands for the development of linear ion traps based on microfabricated three-dimensional chip traps and shift suppression techniques that facilitate low systematic uncertainties for a chain or even a cloud of trapped ions. Similar traps at cryogenic temperatures with the possibility to inject highly charged ions are required for high-resolution spectroscopy this promising new group of ions. Motional heating and drifts in oscillation frequencies will be overcome by developing a quasi-monolithic superconducting RF-resonator trap. These developments will provide unsurpassed control over subatomic particles, strings of singly charged ions, and highly charged ions with applications in precision spectroscopy and fundamental physics. These goals can only be achieved by joining the complementary expertise from the involved groups.