In a significant advancement for quantum physics, the Baryon Antibaryon Symmetry Experiment (BASE) collaboration has successfully maintained the spin coherence of a single antiproton for an unprecedented 50 seconds. This breakthrough, achieved in 2025, not only sets a new record but also positions the antiproton as a potential building block for future quantum technologies and a crucial tool for probing the fundamental symmetries of the universe.
The BASE collaboration, a multinational effort involving researchers from institutions including CERN and Heinrich Heine University Düsseldorf, utilized advanced quantum technologies to isolate and control a single antiproton. The experiment's success in preserving the antiproton's spin coherence for such an extended period is attributed to sophisticated techniques, including the use of multi-Penning trap systems. These systems allow for precise manipulation and observation of individual spin states through a process known as coherent quantum transition spectroscopy. This achievement marks the first time researchers have demonstrated coherent control over a fundamental antimatter particle in this manner, effectively creating an 'antimatter qubit'.
Barbara Maria Latacz, a leading author on the study published in Nature, highlighted the significance of this development, stating that it enables much more precise tests of fundamental symmetries. The ability to maintain quantum coherence for nearly a minute is critical, as environmental interactions typically cause rapid decoherence, hindering such precise measurements. The extended spin coherence time allows for substantially improved comparisons between matter and antimatter, which is vital for testing CPT symmetry – the principle that matter and antimatter should behave identically apart from their opposite charges. While the universe appears to be overwhelmingly composed of matter, the precise behavior of antimatter, as studied by BASE, could offer clues to this cosmic imbalance.
Furthermore, the BASE experiment has made substantial advancements in cooling antiprotons. Recent developments have reduced the cooling time from a previous 15 hours to a mere 8 minutes. This dramatic improvement, as explained by Latacz, significantly cuts down the time needed for extensive measurement cycles, making previously unrealistic timelines feasible and enhancing experimental precision. These advancements in cooling techniques were recognized as a significant contribution to physics, earning a spot among the top ten physics breakthroughs of 2021.
The BASE collaboration's work builds upon years of research in antimatter studies and precision measurements. Their previous achievements include highly precise comparisons of the charge-to-mass ratio between protons and antiprotons, demonstrating their near-identical properties with a precision of 16 parts per trillion. The ongoing research aims to further refine these measurements, potentially uncovering subtle differences that could challenge the Standard Model of particle physics and open new avenues for understanding the universe's fundamental laws.