Disorder in fractional quantum Hall states and the gap atν=5/2

摘要: Theoretical results for the gaps of fractional quantum Hall states are substantially larger than experimental values determined from activated behavior charge transport. The disparity in case enigmatic ν=5/2 state is worrying as it amounts to a factor 20-30. We argue that disorder effects responsible this and show how intrinsic can be extracted measured transport particle-hole symmetric within same Landau level. present theoretical at 7/2, well v= 1/3, 2/5, 3/7, 4/9, based on exact diagonalizations, taking account finite thickness two-dimensional electron layer level mixing effects. find these consistent with inferred gaps. While earlier analyses [Du et al., Phys. Rev. Lett. 70, 2944 (1993)] assumed constant broadening each sample, our depend filling fraction appear scale elementary excitations corresponding state. This result quasiparticle mediated dissipative