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| Author(s): |
Juliana Maria Abreu da Silva Morbec
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Instituto de Física de São Carlos (IFSC/BT) |
| Defense date: | 2009-03-06 |
| Examining board members: |
Klaus Werner Capelle;
Leonardo Paulo Maia;
Andre Luiz Malvezzi;
Wilson Aires Ortiz;
Helena Maria Petrilli
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| Advisor: | Klaus Werner Capelle |
| Abstract | |
In this work, we investigate the effects of orbital magnetism in the three-dimensional electron gas and in open-shell ions in a solid. We derive a closed analytical expression for the exchange energy of the three-dimensional electron gas in strong magnetic fields including the contribution of the second Landau level and arbitrary spin polarization. This calculation generalizes and corrects earlier results available in the literature. Next, we perform a numerical calculation of the exchange energy of the three-dimensional electron gas in a magnetic field, allowing several Landau levels to be occupied, to obtain the exchange energy for arbitrary values of magnetic field and density. In an independent approach, we use the Thomas-Fermi and Thomas-Fermi-Dirac approximations to construct simple model dielectric functions for the three-dimensional electron gas in the strong magnetic field regime (where only the lowest Landau level is occupied). Finally, we establish links between the phenomenological and the first-principles treatment of orbital magnetism in open-shell ions in solids. These links provide a theoretical foundation for the use of orbital polarization terms in Kohn-Sham calculations and allow to obtain approximations to the exchange-correlation functionals of current-density functional theory. (AU) | |