Physicists trap single antimatter particle for a month
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The gist
Northwestern University physicists trapped a single positron for months in a cryogenic Penning trap.
The feat lets researchers probe antimatter's quantum states, a step toward why matter won out.
Background
Gerald Gabrielse is a Northwestern University physicist and director of its Center for Fundamental Physics who oversaw the project and is the paper's senior author; Thomas Myers, a doctoral student in his lab, is first author. Antimatter annihilates on contact with matter, and positrons (antimatter counterparts of electrons) normally survive only a tiny fraction of a second, making them hard to study. The team reported in Physical Review Letters that it held one positron in a wall-less trap and controlled its quantum states, work aimed at precise tests of fundamental physics.
How it unfolded
- Oct 21, 2026Northwestern physicists reported in Physical Review Letters that they trapped a single positron for months, allowing study of its quantum states.
- Oct 21, 2026The positron was held in a cryogenic superconducting vacuum trap cooled to just 300 millikelvins, a fraction of a degree above absolute zero.
- Oct 21, 2026Positrons from a radioactive sodium source were slowed through a single tungsten crystal and confined by electric and magnetic fields in a Penning trap.
- Oct 21, 2026Loading took roughly eight to 11 hours to capture a positron, but repeated loading became unnecessary once one remained trapped.
- Oct 21, 2026Researchers pushed the positron into its lowest energy state and moved it to the next lowest with controlled bursts of microwaves.
- Oct 22, 2026Coverage described the result as the first one-positron quantum cyclotron, with Thomas Myers as first author.
- Oct 23, 2026Coverage noted the work follows the transport of antiprotons by road at CERN earlier this year.
- Oct 24, 2026Coverage framed the achievement as the first demonstration of controlling a single antimatter particle's quantum behavior, with the hard part still ahead.
Who’s saying what
- Expert
- Gabrielse said the big challenge is persuading positrons to slow down and then capturing them, and that holding antimatter requires a container without walls.
- Caution
- RIKEN researcher Stefan Ulmer said trapping an antiparticle is extremely difficult, since any stray particle, burst of light or tiny vibration could disturb it.
- Analysts
- Coverage framed the result as a first in controlling a single antimatter particle's quantum behavior, with the hard part still ahead.