2-DIMENSIONAL MAGNETOEXCITONS - A SHIFTED 1/N APPROACH

The energy spectrum of two-dimensional magnetoexcitons has been calculated using the shifted 1/N expansion method (N the space dimension). It is found that even in the leading-term approximation this approach provides remarkably accurate and simple analytic expressions for the magnetoexciton energies for any magnetic field strength and electron-hole mass ratio. For the infinite-hole-mass exciton (hydrogenic impurity) our results show an excellent agreement with previously reported numerical data in the whole magnetic field range. Higher terms in the expansion which allow a systematic improvement of low-energy values are also considered.