SectionHamiltonian Type flag Default electric_dipole + electric_quadrupole + magnetic_dipole
Terms to be included in the multipolar expansion.
For this type of coupling to make sense, the E field has to be calculated at the center of mass (not averaged).
Options:
electric_dipole:
Adds electric dipole term in length gauge, uses transverse electric field E(t):
$ H_{int} = -e (r.E) $
electric_quadrupole:
Adds electric quadrupole term:
$ H_{int} = \frac{1}{2} e (r . Q . r )] <\math>
where Q is the outer product of gradient and electric field: $ Q_{ij} = \partial_i E_j |_{r=r_0} $
magnetic_dipole:
Adds magnetic dipole term:
$ H_{int} = - i (e \hbar /2m) \sum_i (\vec{B}(r_0).(\vec{r} x \nabla)) $