Calculation of Rydberg energy levels of rubidium in an electric field

Energy levels of Rydberg Rubidium atoms in an external electric field are calculated by Hamiltonian-diagonalization and Coulomb approximation. The results are in agreement with previous studies and with the expected scaling laws. Comparing to electromagnetically induced transparency(EIT) experiments of Rubidium vapour in 90 MHz rf electric field and room temperature of Durham University, we can observe the effect of the presence of ions and oscillating electric field. The BIT experimental results also show larger effective field than theoretical results by a factor of 1.35.