Splitting of Long-Wavelength Modes of the Fractional Quantum Hall Liquid   at $\nu=1/3$
  Resonant inelastic light scattering experiments at $\nu=1/3$ reveal a novel splitting of the long wavelength modes in the low energy spectrum of quasiparticle excitations in the charge degree of freedom. We find a single peak at small wavevectors that splits into two distinct modes at larger wavevectors. The evidence of well-defined dispersive behavior at small wavevectors indicates a coherence of the quantum fluid in the micron length scale. We evaluate interpretations of long wavelength modes of the electron liquid. 
C.F. Hirjibehedin, Irene Dujovne, A. Pinczuk, B.S. Dennis, L.N.   Pfeiffer, K.W. West