Because the confinement depends on the antihydrogen’s magnetic moment, if the spin of the antiatom flips, it is ejected from the magnetic bottle and annihilates with an atom of normal matter. This gives the experimenters an easy way to detect the interaction of light or microwaves with antihydrogen, because photons at the right frequency make the antiatom’s spin flip up or down.
Though the team has trapped up to three antihydrogen atoms at once, the goal is to trap even more for long periods of time in order to achieve greater statistical precision in the measurements.
The ALPHA collaboration also will report in the Nature Physics paper that the team has measured the energy distribution of the trapped antihydrogen atoms.
“It may not sound exciting, but it’s the first experiment done on trapped antihydrogen atoms,” Wurtele said. “This summer, we’re planning more experiments, with microwaves. Hopefully, we will measure microwave-induced changes of the atomic state of the antiatoms.”