Resonant Rayleigh scattering from quantum phases of cold electrons in   semiconductor heterostructures
  Resonant Rayleigh scattering of light from electrons confined in gallium arsenide double quantum wells displays significant changes at temperatures that are below one degree Kelvin. The Rayleigh resonance occurs for photon energies that overlap a quantum well exciton and when electron bilayers condense into a quantum-Hall state. Marked changes in Rayleigh scattering intensities that occur in response to application of an in-plane magnetic field indicate that the unexpected temperature dependence is linked to formation of non-uniform electron fluids in a disordered quantum-Hall phase. These results demonstrate a new realm of study in which resonant Rayleigh scattering methods probe quantum phases of cold electrons in semiconductor heterostructures. 
S. Luin, V. Pellegrini, A. Pinczuk, B.S. Dennis, L.N. Pfeiffer, K.W.   West