arXiv:1712.06059 · Physical Review A
Tunable magic wavelengths for trapping with focused Laguerre-Gaussian beams
Anal Bhowmik, Narendra Nath Dutta, Sonjoy Majumder
Abstract
We present in this paper a theory of dynamic polarizability for an atomic state due to an external field of nonparaxial Laguerre-Gaussian (LG) beam using the sum-over-states technique. A highly correlated relativistic coupled-cluster theory is used to evaluate the most important and correlation-sensitive parts of the sum. The theory is applied on ${\mathrm{Sr}}^{+}$ to determine the magic wavelengths for $5{s}_{1/2}\ensuremath{\rightarrow}4{d}_{3/2},4{d}_{5/2}$ transitions. Results show the variation of magic wavelengths with the choice of orbital and spin angular momenta of the incident LG beam. Also, the tunability of the magic wavelengths is studied by using the focusing angle of the LG beam and its efficiency in the near-infrared region is observed. Evaluations of the wide spectrum of magic wavelengths from infrared to ultraviolet have substantial importance to experimentalists for carrying out high-precision measurements in fundamental physics. These magic wavelengths can be used to confine the atom or ion at the dark central node or at the high-intensity ring of the LG beam.