Excitonsstates in semiconductor quantum wells in a magnetic field

We present a method to calculate the binding energy of exciton s states in any kind of layered structure potential including the case of zero valence- or conduction-band offsets. Furthermore, our numerical resolution of an effective Schr\"odinger equation allows one to take into account the effects of a magnetic field, of arbitrary intensity, perpendicular to the layers. This paper extends the Leavitt and Little method [Phys. Rev. B 42, 11 774 (1990)], which deals only with the 1s state of the exciton in the absence of a magnetic field. Excellent agreement is obtained with experimental results.