Quantum Logic Spectroscopy of (Anti-)Protons

Within the standard model of particle physics, particles and their antiparticles are predicted to have exactly the same modulus of charge, mass, lifetime and g-factor as a result of CPT invariance (invariance under time reversal, charge conjugation and spatial inversion). In this project, we aim to develop a test of CPT invariance by comparing the proton and antiproton g-factors using quantum logic techniques.

This approach had been proposed by D. Heinzen and D. J. Wineland in 1990 [D. J. Heinzen and D. J. Wineland, Phys. Rev. A, 42 (1990); see also D. J. Wineland et al.J. Res. NIST, 103, 259 (1998)]. The basic idea is to couple the (anti-)proton to an atomic "qubit" ion trapped in its vicinity via the Coulomb interaction and to exploit this coupling both for ground state cooling of single (anti-)protons as well as for state readout.

This project uses some of the same techniques as our project on quantum logic and simulation to achieve the desired coupling between the qubit ion and the (anti-)proton. Compared to our quantum logic surface-electrode traps, this project will employ a miniaturized Penning trap in a 5 Tesla superconducting magnet.

This project is part of the BASE collaboration (Baryon-Antibaryon Symmetry Experiment). Within BASE, we collaborate with researchers from RIKEN, Japan, Max-Planck-Institut für Kernphysik, Heidelberg, Universität Mainz, GSI Darmstadt, and the University of Tokyo, Komaba, Japan. We plan to demonstrate quantum logic manipulation of single protons in Hannover and Braunschweig. If successful, the trap and laser systems could be installed at CERN at the BASE beamline for experiments with antiprotons.

QLEDS Penning trap array for quantum logic cooling and readout of single (anti-)protons