ON THE STABILITY OF A WANNIER EXCITON IN A POLAR CRYSTAL
论极性晶体中Wannier激子的稳定性

In this paper, the ground state energy of a wannier exciton is calculated by means of the effective Hamiltonian obtained by one of the authors. It is shown that there is a range of values of the electron-tohole mass ratio a, for which the exciton. is stable with respect to dissociation into a free electron and a free hole.