Properties of confined small systems of electrons in a parabolic quantum dot

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Recent advances in the field of nanotechnology have enabled the precise, controlled fabrication of materials and structures at atomic and molecular scales. In nanoscale territory, the electron's quantum mechanical nature dominates. A class of devices called semiconductor quantum dots has been identified as one of the most promising avenues for meeting the new technological challenges of the 21st century. Quantum dots represent fascinating systems to study novel phenomena of theoretical and practical interest because low dimensionality coupled with the interplay between strong correlations, quantum confinement and magnetic field creates unique conditions for emergence of fundamentally new physics. The properties of confined twodimensional (2D) electronic systems in a semiconductor material that we refer to as 2D semiconductor quantum dots are a topic of intensive ongoing research. A typical 2D semiconductor quantum dot structure holds only a few electrons. As a result, such systems behave differently from standard bulk semiconductor devices given that the discreteness of the electron charge cannot be neglected anymore. The confinement potential of the electrons is generally well approximated by a parabolic well. The main effect of a magnetic field perpendicular to the plane of the quantum dot is to gradually quench the kinetic energy of the electrons as field increases. In this work we consider 2D semiconductor quantum dot systems consisting of few interacting electrons confined in an isotropic parabolic potential. We study the many-electron quantum ground state properties of such systems in presence of a perpendicular magnetic field as the number of electrons is varied using accurate numerical approaches. The results derived from the calculations of the quantum model are then compared to corresponding results for a classical model of point charges confined in a parabolic trap in which such charges interact with a Coulomb potential. We find that, for a wide range of parameters and magnetic fields, the quantum ground state energy is very close to the classical energy of the most stable classical configuration under the condition that the classical energy is properly adjusted to incorporate the quantum zero point motion. © Nova Scicence Publishers, Inc. All rights reserved.

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