CERN Collaboration Traps Antiproton Qubit for One Minute

The BASE collaboration at CERN has, for the first time, demonstrated a functional quantum bit, or qubit, utilising an antiproton. This achievement, detailed in an article published in Nature, involved maintaining a single antiproton in a coherent superposition of two quantum states for a period approaching one minute. The antiproton, the antimatter analogue of the proton, possesses a magnetic moment – effectively behaving as a miniature bar magnet with a defined spin. Researchers exploited this property, inducing transitions between the two spin states and observing coherent quantum behaviour.

The technique employed, coherent quantum transition spectroscopy, allows for precise measurement of these magnetic moment ‘flips’. Maintaining coherence – the preservation of quantum interference effects – is critical, as interactions with the environment typically induce rapid quantum decoherence, suppressing these effects. The prolonged coherence observed – nearing one minute – represents a significant advancement, enabling substantially improved comparisons between matter and antimatter. This capability is anticipated to facilitate high-precision tests of fundamental symmetries, notably charge-parity-time (CPT) symmetry, which posits identical behaviour between matter and antimatter despite the observed matter-antimatter asymmetry in the Universe. The ability to precisely measure and control the quantum state of an antiproton opens avenues for advanced quantum sensing and information processing applications, alongside furthering investigations into the fundamental laws governing particle physics.