Quadratic Stark Effect in theP322States of the Alkali Atoms

The method of pure electric field level-crossing spectroscopy has been used to measure the tensor polarizability of the $5{}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}$ state of potassium. Our result is ${\alpha }_2=-0.263\mathrm{}\left(40\right)\mathrm{}$ MHz/ ${\mathrm{}(\mathrm{k}\mathrm{V}/\mathrm{c}\mathrm{m})\mathrm{}}^2$. Numerical values of the scalar and tensor polarizabilities of the first, second, and third ${}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}$ states of Li, Na, K, Rb, and Cs have been calculated using the Bates-Damgaard technique to evaluate the necessary radial integrals. The polarizabilities show remarkable systematic trends among the various states of the atoms. Our present and previously reported results are compared with previous theoretical and experimental work. The agreement between theoretical and experimental values ranges from fair to excellent.