Competition between neighboring minima in the fractional quantum Hall effect

We report observations of a temperature-dependent competition in the fractional quantum Hall effect in GaAs/AlGaAs heterostructures. Two pairs of neighboring minima in the diagonal resistance ${\rho }_{\mathrm{xx}}$ versus magnetic field exhibit a competition by which the stronger minimum engulfs the weaker minimum as the temperature is decreased. This competition is observed at fractional Landau filling factor ν between the minima at ν=(7/5) and (4/3), and the minima at ν=(8/5) and 3. The strength of the minima at ν=(4/3) and (5/3) relative to one another contrasts with the strength of the ν=(1/3) and (2/3) minima.