ATOMIC SUPERSYMMETRY, RYDBERG WAVE-PACKETS, AND RADIAL SQUEEZED STATES

We study radial wave packets produced by short-pulsed laser fields act ing on Rydberg atoms, using analytical tools from supersymmetry-based quantum-defect theory. We begin with a time-dependent perturbative cal culation for alkali-metal atoms, incorporating the atomic-excitation p rocess. This provides insight into the general wave-packet behavior an d demonstrates agreement with conventional theory. We then obtain an a lternative analytical description of a radial wave packet as a member of a particular family of squeezed states, which we call radial squeez ed states. By construction, these have close to minimum uncertainty in the radial coordinates during the first pass through the outer apsida l point. The properties of radial squeezed states are investigated, an d they are shown to provide a description of certain aspects of Rydber g atoms excited by short-pulsed laser fields. We derive expressions fo r the time evolution and the autocorrelation of the radial squeezed st ates, and we study numerically and analytically their behavior in seve ral alkali-metal atoms. Full and fractional revivals are observed. Com parisons show agreement with other theoretical results and with experi ment.