Cyclotron spin-flip mode as the lowest-energy excitation of unpolarized integer quantum Hall states

Abstract

The cyclotron spin-flip modes of spin unpolarized integer quantum Hall states (ν=2,4,6) have been studied with inelastic light scattering. The energy of these modes is significantly smaller compared to the bare cyclotron gap. Second-order exchange corrections are held responsible for a negative energy contribution and render these modes the lowest-energy excitations of unpolarized integer quantum Hall states.