Deriving the Spectrum, Ch Atoms in electric fields
Problem
Hydrogen's Lamb shift, the 2S1/2-2P1/2 splitting ΔL, is quoted as 0.035285cm−1. Using 1cm−1=29.9792GHz and the crossover condition 3ea0E=ΔL/2 (equating the Stark coupling within the j=21 pair to half the Lamb shift energy), find the field E in Vcm−1 at which hydrogen's n=2 Stark shift changes from quadratic to linear.