Unified theory of symmetry-breaking effects on excitons in cubic and wurtzite structures

A general group-theoretical scheme is developed to discuss any symmetry-breaking effects on the 12-fold $1s$-exciton states originating from an $s$-like and $p$-like electron-hole pair. All the possible effects on the conduction and valence bands are taken into account by an effective Hamiltonian formalism. For the electronhole exchange interaction, the simplest term (including dipole-dipole interaction) is considered. The symmetry-breaking effects treated here can be anything; e.g., a magnetic field, an electric field, stress, the finiteness of exciton wave vector, etc., and even the products of them. As a group-theoretical treatment, this theory includes all the relevant previous theories as special cases.