By using an appropriate coordinate transform we have calculated variational
ly the ground state exciton binding energy in the single square well under
the tilted magnetic field. The dependence of the binding energy to the magn
etic field strength, well width, and the direction of the field is discusse
d. We conclude that for small well widths the exciton binding energy is ver
y sensitive to the tilt angle. (C) 2000 American Institute of Physics. [S00
21-8979(00)05517-1].