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 the electrostatically screened Coulomb interaction of the Yukawa type. Our variational calculation demonstrates that the value of the minimum dipole moment increases as the screening parameter increases. More interestingly, we have found that the dipole’s length has a remarkable effect on the minimum dipole moment; a feature not found for the unscreened case. This effect yields a rapid increase of the value of the minimum dipole moment, particularly for large values of the screening parameter, with the increasing dipole moment’s length. © 1996 The American Physical Society.