Coupling and Dissociation in Artificial Molecules
arXiv:cond-mat/0107014 · doi:10.1007/s100530170133
Abstract
We show that the spin-and-space unrestricted Hartree-Fock method, in conjunction with the companion step of the restoration of spin and space symmetries via Projection Techniques (when such symmetries are broken), is able to describe the full range of couplings in two-dimensional double quantum dots, from the strong-coupling regime exhibiting delocalized molecular orbitals to the weak-coupling and dissociation regimes associated with a Generalized Valence Bond combination of atomic-type orbitals localized on the individual dots. The weak-coupling regime is always accompanied by an antiferromagnetic ordering of the spins of the individual dots. The cases of dihydrogen (H, ) and dilithium (Li, ) quantum dot molecules are discussed in detail.
7 pages. Latex with 4 GIF and 1 EPS figures. Based on an invited talk at the ISSPIC10 conference (see http://www.physics.gatech.edu/isspic10/) A version of the manuscript with high quality figures incorporated in the text is available at http://calcite.physics.gatech.edu/~costas/qds_isspic10.html For related papers, see http://www.prism.gatech.edu/~ph274cy
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