Frequency-dependent polarizabilities of alkali-metal atoms from ultraviolet through infrared spectral regions

We present results of first-principles calculations of the frequency-dependent polarizabilities of all alkali-metal atoms for light in the wavelength range 300–1600 nm, with particular attention to wavelengths of common infrared lasers. We parametrize our results so that they can be extended accurately to arbitrary wavelengths above 800 nm. This work is motivated by recent experiments involving simultaneous optical trapping of two different alkali-metal species. Our data can be used to predict the oscillation frequencies of optically trapped atoms, and particularly the ratios of frequencies of different species held in the same trap. We identify wavelengths at which two different alkali-metal atoms have the same oscillation frequency.

Figure 1

(Color online) The ratios $\alpha \left(\lambda \right)∕m$ of frequency-dependent polarizabilities to the atomic weights for ${}^6\mathrm{Li}$ and ${}^{23}\mathrm{Na}$.

Figure 2

(Color online) The ratios $\alpha \left(\lambda \right)∕m$ of frequency-dependent polarizabilities to the atomic weights for ${}^{40}\mathrm{K}$ and ${}^{87}\mathrm{Rb}$.