Resonant light reflection in the 1/3 Laughlin state

The temperature dependence of the resonant light reflection spectra from the Laughlin liquid in the 1/3 fractional quantum Hall state is measured. It is shown that the resonant reflection lines under conditions corresponding to the formation of the fractional quantum Hall state have a cooperative nature, and their energies do not obey the requirements of the “hidden symmetry”. The energies of spin excitations in the Laughlin liquid are measured using the resonant reflection spectra, and the results of the experiment are compared to the results obtained by solving the Schrödinger equation for several particles.