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Full-Text Articles in Physics
Electron Correlations In An Excited State Of A Quantum Dot In A Uniform Magnetic Field, Marlina Slamet, Viraht Sahni
Electron Correlations In An Excited State Of A Quantum Dot In A Uniform Magnetic Field, Marlina Slamet, Viraht Sahni
Publications and Research
Electron correlations in a two-electron two-dimensional ‘artificial atom’ or quantum dot (with harmonic confining potential) in the presence of a uniform magnetic field in an excited singlet state are studied via quantal density functional theory (QDFT). QDFT allows for the separation of the electron correlations due to the Pauli exclusion principle and Coulomb repulsion, as well as the determination of the contribution of these correlations to the kinetic energy. The QDFT mapping is from the excited state of the quantum dot to one of noninteracting fermions in their ground state possessing the same basic variables of the density and physical …
Electron Correlations In Local Effective Potential Theory, Viraht Sahni, Xiao-Yin Pan, Tao Yang
Electron Correlations In Local Effective Potential Theory, Viraht Sahni, Xiao-Yin Pan, Tao Yang
Publications and Research
Local effective potential theory, both stationary-state and time-dependent, constitutes the mapping from a system of electrons in an external field to one of the noninteracting fermions possessing the same basic variable such as the density, thereby enabling the determination of the energy and other properties of the electronic system. This paper is a description via Quantal Density Functional Theory (QDFT) of the electron correlations that must be accounted for in such a mapping. It is proved through QDFT that independent of the form of external field, (a) it is possible to map to a model system possessing all the basic …
Double Excitations Within Time-Dependent Density Functional Theory Linear Response, Neepa T. Maitra, Fan Zhang, Robert J. Cave, Kieron Burke
Double Excitations Within Time-Dependent Density Functional Theory Linear Response, Neepa T. Maitra, Fan Zhang, Robert J. Cave, Kieron Burke
All HMC Faculty Publications and Research
Within the adiabatic approximation, time-dependent density functional theory yields only single excitations. Near states of double excitation character, the exact exchange–correlation kernel has a strong dependence on frequency. We derive the exact frequency-dependent kernel when a double excitation mixes with a single excitation, well separated from the other excitations, in the limit that the electron–electron interaction is weak. Building on this, we construct a nonempirical approximation for the general case, and illustrate our results on a simple model.
Interpretation Of Electron Correlation In Local-Density Approximation For Exchange, Viraht Sahni, Marlina Slamet
Interpretation Of Electron Correlation In Local-Density Approximation For Exchange, Viraht Sahni, Marlina Slamet
Physics Faculty Publications
We provide a new interpretation of how electron correlations are represented within the local-density approximation for exchange by deducing via Harbola-Sahni theory the corresponding pair-correlation density. The expression differs from that in the literature and contains, in addition to the uniform electron-gas result, a term proportional to the gradient of the density. Thus, the nonuniformity of the electron density is explicitly incorporated in the approximation, and constitutes thereby the reason underlying its success.