Appearance and structure of multiply charged negative ions of hydrogen in intense circularly polarized laser fields

Abstract

We present a theoretical description of the appearance of bound states of atomic multiply charged negative ions of hydrogen in circularly polarized laser fields, using high-frequency Floquet theory (HFFT). Monochromatic circularly polarized fields with frequencies large compared to the binding energy of the dressed ion can (founded by HFFT) induce doubly and triply charged negative ions of hydrogen. The field conditions required to induce these ions are within experimental reach. A circularly polarized field with a wavelength $\ensuremath{\lambda}=456\mathrm{nm}$ and an intensity $I=3.0\ifmmode\times\else\texttimes\fi{}{10}^{17}{\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}$ can induce the appearance of a bound state of ${\mathrm{H}}^{2\mathrm{\ensuremath{-}}},$ whereas a bound state of ${\mathrm{H}}^{3\mathrm{\ensuremath{-}}}$ can be induced by a field with wavelength $\ensuremath{\lambda}=45.6\ensuremath{\mu}\mathrm{m}$ and intensity $I=5.1\ifmmode\times\else\texttimes\fi{}{10}^{13}{\mathrm{W}/\mathrm{c}\mathrm{m}}^{2}.$ We also show that a relativistic description or a low-frequency theory is required in order to determine the appearance of bound states of more highly charged negative ions.