Measurement and numerical calculation of Rubidium Rydberg Stark spectra

Jens Grimmel,Nóra Sándor,Florian Jessen,Markus Mack,Malte Reinschmidt,József Fortágh,Florian Karlewski

doi:10.1088/1367-2630/17/5/053005

Abstract

We report on the measurement of Stark shifted energy levels of 87Rb Rydberg atoms in static electric fields by means of electromagnetically induced transparency (EIT). Electric field strengths of up to 500 V cm−1, ranging beyond the classical ionization threshold, were applied using electrodes inside a glass cell with rubidium vapour. Stark maps for principal quantum numbers n = 35 and n = 70 have been obtained with high signal-to-noise ratio for comparison with results from ab initio calculations following the method described in (Zimmerman et al 1979 Phys. Rev. A 20 2251), which was originally only verified for states around n = 15. We also calculate the dipole matrix elements between low-lying states and Stark shifted Rydberg states to give a theoretical estimate of the relative strength of the EIT signal. The present work significantly extends the experimental verification of this numerical method in the range of both high principal quantum numbers and high electric fields with an accuracy of up to 2 MHz.

Highlights

The response of atoms to static electric fields (DC Stark effect) results in line shifts, state mixing and, for sufficiently large fields, ionisation
We report on the measurement of Stark shifted energy levels of 87Rb Rydberg atoms in static electric fields by means of electromagnetically induced transparency (EIT)
We report on the optical spectroscopy of Stark shifted Rydberg states with principal quantum numbers of n = 35 and n = 70 for electrostatic fields between 0-500 V/cm, ranging beyond the classical ionisation limit

Summary

INTRODUCTION

The response of atoms to static electric fields (DC Stark effect) results in line shifts, state mixing and, for sufficiently large fields, ionisation. Stark maps of 85Rb for n up to 55 were studied in the 1980s for low electric fields using two-photon laser excitation and detecting ionisation from thermal collisions [16]. Many recent experiments on Stark shifts use electromagnetically induced transparency (EIT) [17, 18] This spectroscopic method provides a high resolution of the energy levels [18] and is suitable for the detection of states of high principal quantum numbers. We report on the optical spectroscopy of Stark shifted Rydberg states with principal quantum numbers of n = 35 and n = 70 for electrostatic fields between 0-500 V/cm, ranging beyond the classical ionisation limit. We calculate dipole matrix elements between 5P3/2 and the observed Stark shifted states, which are used to give an estimate for the relative strength of the measured signals

MEASUREMENT OF STARK MAPS

CALCULATION OF STARK MAPS AND DIPOLE MATRIX ELEMENTS

COMPARISON OF MEASUREMENTS AND CALCULATIONS

CONCLUSION