Landau condensation of the quasi-hydrogenic spectrum of caesium

Abstract

Landau condensation of the M=+or-3, odd-parity, quasi-hydrogenic caesium spectra is investigated for fields up to 8 T and for energies ranging +or-120 cm-1 around the threshold. Continuous single-mode dye laser excitation is used. A dominant series of sharp discrete lines is shown to follow the semiclassical predictions from the Landau to the diamagnetic Coulomb regimes where the lines branch to well defined states of the hydrogenic manifolds. For this highly hydrogenic spectrum, the spacing of the resonances near the threshold is shown to be 1.5 h(cross) omega c.