Now, they have used microwaves to flip the spin of the positron. This resulted not only in the first precise determination of the antihydrogen hyperfine splitting, but also the first antimatter transition line shape, a plot of the spin flip probability versus the microwave frequency.
“The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting,” the researchers said.
“From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 MHz, consistent with expectations for atomic hydrogen at the level of four parts in 10,000.”
I am expecting a lot more studies on these anti-hydrogen, especially now that they have a very reliable way of sustaining these things.
The paper is an open access on Nature, so you should be able to read the entire thing for free.