Observation of the Transition to Chaos in the Level Statistics of Diamagnetic Helium
نویسندگان
چکیده
We have investigated level statistics in constant-scaled-energy spectra of the diamagnetic helium atom. In a transversely laser-cooled beam metastable triplet atoms are excited to Rydberg states in the presence of a magnetic field, resolving all resonances. In the regime of regular classical motion level distributions obeying Poisson statistics are observed. Small deviations are attributed to scattering at the nonhydrogenic He core as inferred from closed-orbit theory. The nearest-neighbor spacings in spectra in the chaotic regime demonstrate a clear shift towards Wigner statistics. [S0031-9007(98)07780-1]
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