Summary: Joint institute of GSI Helmholtzzentrum fuer Schwerionenforschung and JGU Mainz, located on the JGU campus. Sections cover accelerator physics, exotic-atom and antimatter precision measurement, and matter-antimatter symmetry tests. Dmitry Budker's section runs table-top precision physics: atomic-vapor and NV magnetometers, zero- to ultralow-field NMR, the GNOME magnetometer network and the CASPEr axion-NMR search. Provides the low-field-magnetics and shielded-environment infrastructure behind much of the Mainz quantum-sensing effort.
Notes:
Duellmann heads nuclear chemistry at JGU (TRIGA reactor site) with joint appointments at GSI and the Helmholtz Institute Mainz, working on the production, chemical separation and characterization of the heaviest elements. For this search the relevant thread is 229Th: his group supplies and prepares the isomeric thorium samples and molecular thorium ions that Wendt's laser spectroscopy and Schmidt-Kaler's ion traps interrogate en route to a nuclear clock, and he is part of the broader radioactive-molecule programme aimed at symmetry-violation searches. Relative to the established NV-ensemble quantum-sensing playbook (DEER, nanoscale NMR, T1 relaxometry at pT/sqrt(Hz) ensemble sensitivity), the pivot is toward the next frontier of frequency metrology, where the 'sensor' is a nucleus rather than an electron shell -- an unusually good chemistry/physics interface for a postdoc.
Quantenbit operates segmented micro-structured Paul traps for scalable trapped-ion quantum information and, increasingly, for quantum sensing. Directions: (i) trapped Rydberg ions -- combining the tight confinement of a Paul trap with the giant polarizability of Rydberg states, which is simultaneously a fast-gate resource and an extremely sensitive electric-field probe; (ii) motional-mode sensing of electric fields and surface noise; (iii) deterministic single-ion implantation, where a cold ion is extracted from the trap and implanted with nm-scale placement -- directly relevant to building NV/donor arrays with known ion counts, and to single-ion detection validation; (iv) TACTICa, applying ion-trapping and quantum-logic spectroscopy to 229Th toward a nuclear clock; (v) single-atom heat engines and quantum thermodynamics. Relative to the established NV-ensemble quantum-sensing playbook (DEER, nanoscale NMR, T1 relaxometry at pT/sqrt(Hz) ensemble sensitivity), the deterministic-implantation line is the natural upstream complement: it is the route to engineering NV ensembles/arrays with controlled density rather than relying on stochastic implantation. Strong local coupling to Budker (Th-229, exotic physics) and Wendt (laser ionization).
Walz works on precision spectroscopy of exotic atoms and antimatter. The group is known for continuous-wave Lyman-alpha (121.6 nm) laser sources -- the enabling technology for laser cooling of antihydrogen -- and for antihydrogen and positronium spectroscopy aimed at CPT tests and at antimatter gravity measurements, in collaboration with CERN antiproton-decelerator experiments. Complementary work at Mainz covers laser development, exotic-atom trapping and detection. Relative to the established NV-ensemble quantum-sensing playbook (DEER, nanoscale NMR, T1 relaxometry at pT/sqrt(Hz) ensemble sensitivity), this is a fundamental-symmetry pivot: the sensing content is in ultra-stable lasers, extreme-vacuum trapping and single-particle detection rather than solid-state spins, and it suits a postdoc looking to move from quantum sensors toward fundamental-physics tests.