Europhys. Lett, 44 (6), pp. 766-771 (1998)

Enhancement of quantum dot peak-spacing fluctuations
in the fractional quantum Hall regime

E. Shopen and Y. Meir

Department of Physics, Ben-Gurion University - Beer Sheva 84105, Israel

(received 5 August 1998; accepted in final form 26 October 1998)

PACS. 73.61 - Electrical properties of specific thin films and layer structures (multilayers, superlattices, quantum wells, wires, and dots).
PACS. 73.40Hm - Quantum Hall effect (integer and fractional).
PACS. 74.40 - Fluctuations (noise chaos, nonequilibrium superconductivity, localization, etc.).


The fluctuations in the spacing of the tunneling resonances through a quantum dot have been studied in the quantum Hall regime. Using the fact that the ground state of the system is described very well by the Laughlin wave function, we were able to determine accurately, via classical Monte Carlo calculations, the amplitude and distribution of the peak-spacing fluctuations. Our results clearly demonstrate a big enhancement of the fluctuations as the importance of the electronic correlations increases, namely as the density decreases and filling factor becomes smaller. We also find that the distribution of the fluctuations approaches a Gaussian with increasing density of random potentials.


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