Effective Mass and $\mathit{g}$ Factor of Four-Flux-Quanta Composite Fermions

We investigate the properties of composite fermions with four attached flux quanta through tilted-field experiments near Landau level filling factor $\nu =3/4\mathrm{}$. The observed collapse of fractional quantum Hall gaps in the vicinity of this quarter-filling state can be comprehensively understood in terms of composite fermions with mass and spin. Remarkably, the effective mass and $g$ factor of these four-flux-quanta composite fermions around $\nu =3/4\mathrm{}$ are very similar to those of two-flux-quanta composite fermions around $\nu =3/2\mathrm{}$.