Quasi-Landau spectrum of a hydrogen like atom in a high magnetic field

Abstract

A two dimensional semiclassical approximation is used to examine the sigma polarization spectrum of a hydrogen like atom in a strong magnetic field. Resonances above the zero field ionization limit are found and their energy separations are computed over the region from the ionization limit to 40 h(cross) omega _c above, where omega _c is the cyclotron frequency, for magnetic fields of 10, 17, 25, 32, 40 and 47 kG. At the ionization limit the separation between resonances is found to be 1.500 h(cross) omega _c, independent of magnetic field strength, which is in agreement with a separation of 1.5 h(cross) omega _c observed experimentally by Garton and Tomkins (1969) in the sigma polarization spectrum of barium in a magnetic field of 24 kG. The energy separations are found to decrease above the ionization limit toward the value h(cross) omega _c, which is characteristic of the levels of a free electron in a homogeneous magnetic field.