Motional Stark Effect on Li Vapor Photoabsorption in High Magnetic Fields

Abstract

Calculation of the motional Stark effect for $B\ensuremath{\sim}50$ kG shows it to become dominant along Rydberg series of light elements at $T\ensuremath{\sim}1000\ifmmode^\circ\else\textdegree\fi{}$C before the diamagnetic shift changes the spectrum from Rydberg to Landau type, thus accounting for the $\frac{1}{2}\ensuremath{\hbar}{\ensuremath{\omega}}_{c}$ spacing observed in Li. This spacing is preserved when both of the competing effects---motional Stark and Landau modulation---are strong. The spectrum appears to depend critically on the relative position of the thresholds for the onset of the two effects.