Performance of the coupled cluster singles and doubles method on two-dimensional quantum dots
(English)Manuscript (preprint) (Other academic)
An implementation of the coupled-cluster single- and double excitations (CCSD) method on two-dimensional quantum dots is presented. Advantages and limitations are studied through comparison with other high accuracy approaches for two to eight confined electrons. The possibility to effectively use a very large basis set is found to be an important advantage compared to full configuration interaction implementations. For the two to eight electron ground states, with a confinement strength close to what is used in experiments, the error in the energy introduced by truncating triple excitations and beyond is shown to be on the same level or less than the differences in energy given by two different Quantum Monte Carlo methods. Convergence of the iterative solution of the coupled cluster equations is, for some cases, found for surprisingly weak confinement strengths even when starting from a non-interacting basis. The limit where the missing triple and higher excitations become relevant is investigated through comparison with full Configuration Interaction results.
electronic structure, electron correlation methods, coupled cluster, coupled cluster singles and doubles, quantum dot, two-dimensional, many-body physics, many-body perturbation theory
Condensed Matter Physics
Research subject Physics
IdentifiersURN: urn:nbn:se:su:diva-38861OAI: oai:DiVA.org:su-38861DiVA: diva2:317058