Extended Data Fig. 3: Simulated correlations between the longitudinal and transverse energies within the same samples in the cooling experiment.
a–d, Red dots show the values of true longitudinal (EL) and transverse (ET) energies of simulated antihydrogen atoms at the time of spin flip, for the four different series. The blue dashed lines depict the median longitudinal and transverse energies (cf. Fig. 4) and the black crosses indicate their mean values. Note the appearance of an intense peak near EL and ET ≈ 0, in the ‘stack and cool’ (a) and cooling (b) series, compared with the no-laser series (c), indicating strong three-dimensional cooling. The distributions show that the total energy, EL + ET is bound by the trap depth of about 50 μeV. This results in anti-correlation between EL and ET for the atoms with a total energy comparable to the trap depth. This anti-correlation is enhanced in the heating series (d), where the population of the coldest atoms (near EL and ET ≈ 0) are removed by the laser heating. These features in the simulated events qualitatively explain the observations in Fig. 4.
