Inelastic Light Scattering in Electron Wonderland: Quantum Liquids and Phase Transitions

The inelastic light scattering method has been used extensively to study collective excitations of low dimensional electron systems in semiconductor quantum structures. This communication presents very short summary of some recent light scattering research in high quality two-dimensional systems. The studies considered here explore effects. The highlights are in three areas: (1) The measurements of collective gap observations of collective excitation modes of electron fluids at temperatures lower than 100mK; (2) The exploration of intriguing instabilities of 2D electron systems at ultra-low density; (3) A study of the strong interactions that trigger soft-mode quantum phase transitions in electron double-layers.