The elusive antihydrogen atom has been manipulated using microwaves, providing the first glimpse of an "anti-atomic fingerprint." 

Antimatter is a staple of science fiction, but it also stands out as one of the biggest mysteries of science fact. Fundamental theories predict perfect symmetry between matter and antimatter, but the glaring absence of antimatter in our universe suggests there might be a difference. Enter microwave spectroscopy, one of the most sensitive techniques for probing the structure of atoms.

"This study demonstrates the feasibility of applying microwave spectroscopy to fiendishly difficult-to-handle anti-atoms," says co-author Walter Hardy from the University of British Columbia (UBC). "ALPHA is about to enter an intensive upgrade phase that promises to create an ever-clearer picture of the inner structure of anti-matter atoms."

The present measurement involved confining anti-atoms in a magnetic trap and irradiating them with microwaves. Precise tuning of the microwave frequency and magnetic field enabled researchers to hit an internal resonance, kicking atoms out of the trap, and revealing information about their properties.

Hardy and lead author Mike Hayden of Simon Fraser University designed the apparatus for this latest experiment, working closely with PhD candidates Mohammad Ashkezari of FsU and Tim Friesen from the University of Calgary. Meanwhile, researchers from the TRIUMF laboratory and York University teased faint signals from a sophisticated detector system, pinpointing matter-antimatter annihilation events.

Animation of the ALPHA apparatus used by CERN researchers to manipulate antihydrogen atoms using microwaves, providing the first glimpse of an "anti-atomic fingerprint." Credit: ALPHA collaboration (CERN)

"Hydrogen is the most abundant element in the universe, and we understand its structure extremely well," says ALPHA collaboration spokesperson Jeffrey Hangst of Aarhus University in Denmark. "Now we can finally begin to coax the truth out of antihydrogen. Are they different? Today, we can confidently say 'time will tell.'"

Study published in Nature.