Magnetism of quantum dot clusters: A Hubbard model study

Abstract

Magnetic properties of two and three-dimensional clusters of quantum dots are studied with exact diagonalization of a generalized Hubbard model. We study the weak coupling limit, where the electrons interact only within a quantum dot and consider cases where the second or third harmonic oscillator shell is partially filled. The results show that in the case of half-filled shell the magnetism is determined by the antiferromagnetic Heisenberg model with spin 1/2, 1 or 3/2, depending on the number of electrons in the open shell. For other fillings the system in most cases favors a large total spin, indicating a ferromagnetic coupling between the dots.

9 pages, 9 figures

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Cited by in corpus (4)

• Ground-state properties of the one-dimensional attractive Hubbard model with confinement: a comparative study
• 2kF-Friedel to 4kF-Wigner oscillations in one-dimensional Fermi gases under confinement
• Phase separation in optical lattices in a spin-dependent external potential
• Double occupancies in confined attractive fermions on optical lattices