Measurements of the effective mass and scattering times of composite fermions from magnetotransport analysis

Abstract

An experimental analysis of the fractional quantum Hall effect is described in which oscillations in ${\mathrm{\ensuremath{\rho}}}_{\mathit{x}\mathit{x}}$ are treated as Shubnikov--de Haas oscillations of the composite fermions (CF) formed by a flux attachment transformation. We find a CF effective mass of 0.5${\mathit{m}}_{\mathit{e}}$ at zero effective field which increases weakly with effective magnetic field at a rate independent of carrier density. The CF quantum scattering times are the same as for the underlying single particle electron states.