Single quasiparticle localization in FQH states

The interplay between interaction and disorder-induced localization is of fundamental interest. In this talk, we address the localization physics of quasiparticles in the fractional quantum Hall state, where both interaction and disorder have nonperturbative consequences. Localized quasiparticle excitations of FQH states are well described using composite fermion theory. We provide compelling evidence that the localization problem of a single quasiparticle of the fractional quantum Hall state at filling factor ν=n/(2n+1) has a surprising one-to-one correspondence to the localization of a single electron in the (n+1)th Landau level in an effective reduced magnetic field. We speculate  that by analogy to the localization in integer quantum Hall effect, this leads to predictions in the fractional quantum Hall regime regarding the existence of extended states at  some critical energy, and the nature of the divergence of the localization length as this energy is approached.