V. Kagalovsky et al., LANDAU-LEVEL MIXING AND EXTENDED STATES IN THE QUANTUM HALL-EFFECT, Physical review. B, Condensed matter, 52(24), 1995, pp. 17044-17047
We study the energies of extended states for two coupled Landau bands
within a network model as a function of Delta, the bare energy separat
ion of extended states in the absence of level mixing. As Delta increa
ses the energy separation of the extended states becomes less than the
bare energy separation, i.e., at high-level separation, level repulsi
on changes into level attraction. The level attraction leads to a mini
mum in the energy of the lower state at a finite magnetic field, consi
stent with level floating at low fields. For a spin-split Landau level
we predict level attraction at high magnetic fields.