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Proceedings Paper

Quantum dots: electrons in a new dimension
Author(s): Trey P. Smith III
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Paper Abstract

Quantum dots represent a new class of electronic structures where the electronic configuration and degree of confinement or coupling can be tuned at will. These artificial mesoscopic structures mimic many atomic effects with a tremendous degree of flexibility. We have studied the transition from isolated to coupled quantum dots in quantum-dot and lateral-surface-superlattice structures. Our maguetocajacitance measurements probe three distinct regimes: a superlattice regime; a tight-bindin.g regime; and an isolated-quantum-dots regime. In the presence of an external magnetic field we find that the coupling of the magnetic flux with the periodic potential depends on the strength of the potential modulation. In strongly-coupled quantum wires and quantum dots, the commensurability between the superlattice period and the cyclotron orbit is reflected in a modification of the envelope of the magnetocapacitance oscillations. In weakly-coupled quantum dots, a new structure is observed. Aperiodic oscillations in the density of states are related to fractal-like behavior in the energy dispersion relation first predicted by Ilofstadter. In completely isolated quantum wires or quantum dots, the canonical magnetocapacitance oscillations are recovered with a Zeeman bifurcation of the states produced by the interplay of magnetic and spatial quantization. We will present our experimental work in light of theoretical models and discuss the fundamental physical phenomena that dominate the the.rmodynamic properties of electrons in quantum dots.

Paper Details

Date Published: 1 October 1990
PDF: 8 pages
Proc. SPIE 1284, Nanostructure and Microstructure Correlation with Physical Properties of Semiconductors, (1 October 1990); doi: 10.1117/12.20768
Show Author Affiliations
Trey P. Smith III, IBM/Thomas J. Watson Research (United States)

Published in SPIE Proceedings Vol. 1284:
Nanostructure and Microstructure Correlation with Physical Properties of Semiconductors
Harold G. Craighead; J. Murray Gibson, Editor(s)

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