Dokument: Interacting Electrons in Quantum Dots with Strong Rashba Spin-Orbit Coupling
| Titel: | Interacting Electrons in Quantum Dots with Strong Rashba Spin-Orbit Coupling | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=38837 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20160630-132600-0 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | MSc Naseri Jorshari, Amin [Autor] | |||||||
| Dateien: |
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| Beitragende: | Prof. Dr. Egger, Reinhold [Gutachter] Prof. Dr. Heinzel, Thomas [Gutachter] | |||||||
| Stichwörter: | Condensed Matter Physics | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 530 Physik | |||||||
| Beschreibung: | In this thesis, we present a study of interacting electrons confined in a two-dimensional space in the presence of a parabolic trap and strong Rashba spin-orbit coupling. The system is characterized by dimensionless parameters for the Rashba coupling and the interaction strength. At the single-particle level, the energy spectrum shows Landau-like bands plus a decoupled rotor expressed in terms of the total angular momentum. The
low-energy physics take place on a ring in momentum space. The significant consequence is that two classes of interactions are boosted, namely, interaction of Kramers pairs and exchange interaction. The ground states of the system are discussed in two parts. In the first part, we predict that an interplay between Coulomb interaction and strong Rashba coupling leads to a transition to orbital ferromagnetism in few-electron, up to ten electrons, quantum dots. In the regime of ultrastrong Rashba coupling, for two electrons, an analytical study shows that an arbitrarily weak interaction induces a large magnetization, which reflects that the orbital angular momentum is behind the effect. For finite but large Rashba coupling, the results of exact-diagonalization technique, for two and three electrons, indicate that a spontaneous magnetization emerges if the interaction strength exceeds a critical value. Finally, a Hartree-Fock calculation for number of electrons up to N = 10 shall be given which reproduces the effect qualitatively. In the second part, we present the study of the many-body system containing large but finite number of electrons. For very weak interactions, the Hamiltonian is bosonized and several correlation functions are computed. Remarkably, we show that Kramers pairs are correlated strongly. Moreover, we establish a connection between our system and the well-studied Richardson pairing model and 1D Heisenberg XXZ spin chain. | |||||||
| Lizenz: |  Urheberrechtsschutz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät | |||||||
| Dokument erstellt am: | 30.06.2016 | |||||||
| Dateien geändert am: | 30.06.2016 | |||||||
| Promotionsantrag am: | 30.03.2015 | |||||||
| Datum der Promotion: | 10.07.2015 |
