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Abstract:
Giant fluctuations in the 2D-electron recombination radiation were studied in structures with a single or double GaAs quantum well under quantum Hall effect conditions. It is established that, if these conditions are exactly satisfied, the amplitude of the 2D-electron photoluminescence (PL) intensity is several orders of magnitude higher than the noise level, with the noise having a normal (Poisson) distribution. The fluctuations in the PL line intensity are accompanied by a jumpwise change in the line positions. Analogous jumps were also observed in the spectra of inelastic light scattering by 2D electrons in structures with a single GaAs quantum well. The fluctuation processes are correlated over macroscopic distances. The characteristic correlation length is 1-2 mm. The spectral density of giant fluctuations was found to exhibit narrow peaks. The ratios of the frequencies of these peaks are equal to those of Fibonacci numbers. The appearance of such frequencies in the fluctuation spectrum indicates that the fluctuations studied bear a resemblance to processes occurring in open dissipative dynamic systems. The methods developed in the theory of these systems can, in principle, be used to study giant fluctuations.
