Observation of strong electronic correlation for highly excited double Rydberg states of ytterbium

Abstract

Using five-laser resonance excitation in combination with a method of sequential ionization by a pu1sed and a constant electric field, we have observed the nearly pure spectra (the ion resonance back-

Structure and electron dynamics of planetary states of Sr below the Sr+ 7d and 8p thresholds

“…As the degree of excitation of both electrons increases (n 1 and n 2 large), spectra associated with double-Rydberg series becoming increasingly complex because the density of states increases and Rydberg-series interactions become ubiquitous. Several electrostatic models were developed to qualitatively describe the energy-level structure and two-electron wavefunctions of the highangular-momentum double-Rydberg states measured in alkaline-earth-metal atoms [9,10,17,[27][28][29][30][31]. They describe the correlations between the two Rydberg electrons of such systems as the polarization of the fast inner electron by the electric field of the slow outer electron, the so-called frozen-planet approximation [9].…”

Interacting asymmetric double Rydberg series: the Ba 8snl(l= 5) + 5fjn′l′ case

“…Those, as well as ongoing, experiments and subsequent theoretical developments [2] led to the discovery of propensity rules dictating both autoionization and, more significantly, single-photon excitation from the ground state thus posing severe limitations to the accessible doubly excited state symmetries. As an alternative to these constraints, correlation effects between two highly and asymmetrically excited electrons out of an ionic closed shell core were studied in alkaline earth [3][4][5][6][7][8][9][10][11][12][13] and other quasi-two-electron atoms [14]. Due to their relatively low double ionization limits, these atoms allow for a laser-based sequential multiphoton transfer of each valence electron to a Rydberg state.…”