Magnetoexciton binding energies in a quantum wire

Binding energies of the Is and 2p +/- states of a heavy-hole Wannier excito n are calculated in an infinite-length cylindrical GaAs-Ga1-xAlxAs quantum wire, under the action of a magnetic field applied in the axial direction o f the wire. The calculations are made using a variational method and the ef fective-mass approximation for a finite confinement potential. Also, the tr ansition energies 1s --> 2p +/- are calculated for the same system. We have found that 2p +/- states are not bounded for some values of the radius of the wire and of the applied magnetic field. We show how the applied magneti c field splits the degeneracy of the states with n = 2. Our results are com pared with those obtained by other authors and with recent experimental res ults.