Two-dimensional charged electron–hole complexes in magnetic fields: keeping magnetic translations preserved

Eigenstates of two-dimensional charged electron–hole complexes in magnetic fields are considered. The operator formalism that allows one to partially separate the center-of-mass motion from internal degrees of freedom is presented. The scheme using magnetic translations is developed for calculating in strong magnetic fields the eigenspectra of negatively charged excitons X−, a bound state of two electrons and one hole.