BOUND ELECTRONIC STATES IN A STATICALLY SCREENED ELECTRIC-DIPOLE POTENTIAL

The problem of the minimum value of the dipole moment needed to assure the existence of a bound electronic state has been addressed for thr electrostatically screened Coulomb interaction of the Yukawa type. Our variational calculation demonstrates that the value of the minimum di pole moment increases as the screening parameter increases, More inter estingly, we have found that the dipole's length has a remarkable effe ct on the minimum dipole moment; a feature not found for the unscreene d case. This effect yields a rapid increase of the value of Ihs minimu m dipole moment, particularly fur large values of the screening parame ter, with the increasing dipole moment's length.