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

TL;DR

This study investigates how electron correlations in quantum dots within the fractional quantum Hall regime significantly amplify peak-spacing fluctuations, with results supported by Monte Carlo calculations.

Contribution

It provides the first detailed analysis of peak-spacing fluctuations in the fractional quantum Hall regime using classical Monte Carlo methods.

Findings

Fluctuations increase as electronic correlations grow stronger.

Distribution of fluctuations tends toward Gaussian with more random potential.

Enhanced fluctuations are linked to decreased density and smaller filling factors.

Abstract

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 wavefunction, 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.