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

References in corpus (5)

• Evidence for Superfluidity of Ultracold Fermions in an Optical Lattice
• Finite temperature phase diagram of a polarized Fermi gas in an optical lattice
• Luther-Emery Phase and Atomic-Density Waves in a Trapped Fermion Gas
• Electronic states in a magnetic quantum-dot molecule: phase transitions and spontaneous symmetry breaking
• Magnetic phases of one-dimensional lattices with 2 to 4 fermions per site