Ephemeral antimatter atoms pinned down in milestone laser test

@article{Castelvecchi2016EphemeralAA,
  title={Ephemeral antimatter atoms pinned down in milestone laser test},
  author={Davide Castelvecchi},
  journal={Nature},
  year={2016}
}
Ability to do spectroscopy on antihydrogen may provide new test of fundamental physics. 

References

Observation of the 1S–2S transition in trapped antihydrogen
TLDR
The observation of the 1S–2S transition in magnetically trapped atoms of antihydrogen is reported, it is determined that the frequency of the transition, which is driven by two photons from a laser at 243 nanometres, is consistent with that expected for hydrogen in the same environment.