SPIN-ORBIT SCATTERING AND SPIN-SPLITTING IN THE QUANTUM HALL-EFFECT

We study dynamics of electrons in a magnetic field using a network mod el with two channels per link with random mixing, while the intrachann el potential is periodic (nonrandom); the channels represent two-spin states. We consider channel mixing as function of the energy separatio n Delta of tile two extended states. We show that for Delta < 0.5 the system has only one extended state, and a localization length diverges approaching it with a nontrivial critical exponent nu approximate to 1.1, whereas for larger Delta a transition to a typical quantum Hall b ehavior with two extended states occurs. and the critical exponent bec omes nu approximate to 2.5.