Quenching of exciton diamagnetic shifts in polar, layered materials

A theory for Wannier excitons in a magnetic field or arbitrary strength, including both anisotropy and exciton-phonon coupling, is presented. Both the anisotropy and the exciton-phonon coupling are shown to considerably quench the shifts of the energy levels in the magnetic field. Results are presented for PbI2 and compared with recent experimental data. © 1978.