By Amit Malewar Published: August 1, 2025
Collected at: https://www.techexplorist.com/first-demonstration-antimatter-qubit/100536/
Coherent quantum transition spectroscopy is a super-precise method scientists use to explore tiny particles and test fundamental physics theories. It’s already helped measure the magnetic properties of protons and deuterons with highly accurate results, we’re talking resolutions better than one part in a trillion!
But these studies always involved large groups of particles. Until now, no one had applied this technique to a single, free nuclear spin.
Here enters the BASE experiment at CERN: They successfully trapped a single antiproton (the antimatter twin of a proton) and made it flip between two quantum states smoothly, for nearly a whole minute.
That’s the first-ever demonstration of an antimatter qubit, a quantum bit made from antimatter. This opens up new ways to study how matter and antimatter differ, with super-high precision.
The BASE collaboration at CERN has pulled off a stunning feat: they’ve used a system of electromagnetic Penning traps to gently “push” a single antiproton into a smooth quantum oscillation between spin states, like nudging a swing at just the right moment. The antiproton behaves as a quantum bit (qubit), meaning its spin can point in multiple directions at once when unobserved, a phenomenon called quantum superposition.
This is the first time coherent quantum control has been demonstrated on a single antimatter particle, not just a group. The experiment used a multi-trap system to isolate, manipulate, and measure the antiproton’s spin with extreme precision.
BASE previously showed that the magnetic moments of protons and antiprotons are identical to within a few parts-per-billion, supporting the idea of CPT symmetry, a cornerstone of the Standard Model. If even a tiny difference were found, it could hint at new physics and help explain why the universe is made mostly of matter, not antimatter.
Previously, attempts to study antiproton spin were clouded by noisy data, magnetic field fluctuations, and interference muddled the quantum transitions. But the BASE team at CERN didn’t settle for fuzziness. They upgraded their setup to eliminate these decoherence effects, allowing for the first-ever coherent spectroscopy of a single antiproton’s spin.
They achieved a spin coherence time of 50 seconds, meaning the antiproton stayed in a stable quantum rhythm for nearly a minute. This marks the birth of the first antimatter qubit, a major milestone in quantum physics. It opens the door to applying coherent spectroscopy to individual particles, matter, and antimatter for ultra-precise experiments.
Future measurements of the antiproton’s magnetic moment could be 10 to 100 times more accurate, pushing the boundaries of the Standard Model.
Qubits are the building blocks of quantum computers and can hold much more complex information than regular bits. BASE has created a special qubit using antimatter, but it’s mainly useful for advanced physics research, not everyday tech yet.
To improve measurements even more, scientists developed BASE-STEP, a system that safely transports trapped antimatter particles to quieter magnetic locations, helping them get much more precise results.
“Once it is fully operational, our new offline precision Penning trap system, which will be supplied with antiprotons transported by BASE-STEP, could allow us to achieve spin coherence times maybe even ten times longer than in current experiments, which will be a game-changer for baryonic antimatter research,” says lead author of the paper, Barbara Latacz.
Journal Reference
- Latacz, B.M., Erlewein, S.R., Fleck, M. et al. Coherent spectroscopy with a single antiproton spin. Nature (2025). DOI: 10.1038/s41586-025-09323-1
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