The unifying role of effective field in the composite fermion model of the fractional quantum Hall effect

Abstract

Fractional Quantum Hall Effect measurements in 50 T pulsed magnetic fields, are analysed in the Composite Fermion (CF) model. Energy gaps of all fractions in the principal series around v = 1/2 show a simple, sample independent, increase with the CF effective field following B *. The spin polarised state at v = 5/3 follows exactly the same behaviour, but for mixed spin states like 4/3 the energy gap collapses when B* > 1T.