Effective mass and 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 v = 3/4. The observed collapse of fractional quantum Hall gaps in the vicini ty of this quarter-filling state can be comprehensively understood in terms of composite fermions with mass and spin. Remarkably, the effective mass a nd g factor of these four-flux-quanta composite fermions around v = 3/4 are very similar to those of two-flux-quanta composite fermions around v = 3/2 . [S0031-9007(98)08208-8].