Final Published Version
Physical Review Letters
An atomic electron is prepared in a state closely analogous to Schrödinger’s coherent superposition of “live cat” and “dead cat.” The electronic state is a coherent superposition of two spatially localized wave packets separated by approximately 0.4 mm at the opposite extremes of a Kepler orbit. State-selective ionization is used to verify that only every other atomic level is populated in the “cat state,” and a Ramsey fringe measurement is used to verify the coherence of the superposition.
© 1996 by the American Physical Society. The publisher's version of the article can be found at http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.77.1913
Michael W. Noel and C. R. Stroud, Jr., "Excitation of an Atomic Electron to a Coherent Superposition of Macroscopically Distinct States," Phys. Rev. Lett. 77, 1913 (1996).