Magic wavelengths for the 2 S-3 -%26gt; 2 S-1 transition in helium

作者：Notermans R P M J W; Rengelink R J; van Leeuwen K A H; Vassen W^*

来源：Physical Review A, 2014, 90(5): 052508.

DOI：10.1103/PhysRevA.90.052508

We have calculated ac polarizabilities of the 2 S-3 and 2 S-1 states of both He-4 and He-3 in the range 318 nm to 2.5 mu m and determined the magic wavelengths at which these polarizabilities are equal for either isotope. The calculations, only based on available ab initio tables of level energies and Einstein A coefficients, do not require advanced theoretical techniques. The polarizability contribution of the continuum is calculated using a simple extrapolation beyond the ionization limit, yet the results agree to better than 1% with such advanced techniques. Several promising magic wavelengths are identified around 320 nm with sufficient accuracy to design an appropriate laser system. The extension of the calculations to He-3 is complicated due to the additional hyperfine structure, but we show that the magic wavelength candidates around 320 nm are predominantly shifted by the isotope shift.

• 出版日期2014-11-13