  We introduce a spin-orbit assisted electron-phonon (e-ph) coupling mechanism
for carriers in semiconductor quantum wells and predict qualitatively the form
and shape of anticrossings between the cyclotron resonance (CR) and optical (LO
and TO) phonons. Since this e-ph interaction involves the electron spin it
makes the predicted TO-CR anticrossing dependent on the filling factor and
therefore on the polarization of the 2D electron gas in the quantum well.
