  The spin degree of freedom in quantum phases of the second Landau level is
probed by resonant light scattering. The long wavelength spin wave, which
monitors the degree of spin polarization, is at the Zeeman energy in the fully
spin-polarized state at $\nu$=3. At lower filling factors the intensity of the
Zeeman mode collapses indicating loss of polarization. A novel continuum of
low-lying excitations emerges that dominates near $\nu$=8/3 and $\nu$=5/2.
Resonant Rayleigh scattering reveals that quantum fluids for $\nu<3$ break up
into robust domain structures. While the state at $\nu$=5/2 is considered to be
fully polarized, these results reveal unprecedented roles for spin degrees of
freedom.
