  We observe geometric resonance features of composite fermions on the flanks
of the even denominator {\nu} = 1/2 fractional quantum Hall state in
high-mobility two-dimensional electron and hole systems confined to wide GaAs
quantum wells and subjected to a weak, strain-induced, unidirectional periodic
potential modulation. The features provide a measure of how close to {\nu} =
1/2 the system stays single-component and supports a composite fermion Fermi
sea before transitioning into a {\nu} = 1/2 fractional quantum Hall state,
presumably the two-component {\Psi}331 state.

Mesoscale and Nanoscale Physics