Signatures of composite-fermion metals in electron bilayers at νT=1

Composite-fermion metals occur in the quantum Hall bilayers at total Landau level filling fraction νT=1 as the tunneling gap ΔSAS collapses by application of in-plane magnetic fields. Experimental evidence is obtained from the observation of a spin continuum below the Zeeman energy by resonant inelastic light scattering. These low-lying spin modes are assigned to quasi-particle excitations, where spin and composite-fermion Landau level index change simultaneously.