Physicists working with the BASE experiment at CERN have created the first quantum bit based on antimatter, coherently manipulating the spin of a single antiproton held in a Penning trap. In tests reported in Nature on 24 July, the team drove controlled Rabi oscillations between the particle’s ‘up’ and ‘down’ spin states and maintained coherence for nearly 60 seconds—orders of magnitude longer than previous attempts with antiparticles. The advance gives researchers a new tool for ultra-precise comparisons between matter and antimatter, a critical check on the standard model’s CPT symmetry. By turning the antiproton into a stable qubit, the BASE group expects to refine measurements of its magnetic moment by a factor of 10 to 100, potentially exposing tiny deviations that could hint at new physics. While practical quantum processors built from antimatter remain theoretical, the result demonstrates that established quantum-information techniques can be extended to antiparticles and lays technical groundwork for future high-precision spectroscopy and metrology.