The main topic of this project is the so called Edelstein effect. This recently discovered effect consists in the possibility of converting an electric field (a current) into a magnetization in materials that fulfill specific characteristics, more specifically materials where an effective Rashba spin-orbit coupling is present. The Edelstein effect is appealing to the scientific community from the fundamental physics point of view as well as from the technological point of view. In fact the possibility of efficiently converting an electric signal into a magnetic signal could revolutionize the current information storage technology. In this project, after a study of basic concepts of solid state physics: crystal structure, Bloch's theorem, spin-orbit coupling; we addressed the study of the basics of a powerful numerical tool, called density functional theory (DFT), for predicting the electronic properties of solids. This tool provides us with all the needed quantities for numerically calculating any kind of linear response, which we show that the Edelstein effect is a specific form of. Using a specific implementation of DFT, called augmented spherical wave (ASW), we calculate the Edelstein effect in iron and copper (where no effect is expected) and manganese silicide (where the effect is expected to appear). We also perform a systematic study on how the Edelstein effect depends on the symmetry of the material and the magnitude of the spin-orbit coupling. The calculations showed promising results from which we concluded that the numerical methods used could clearly distinguish between the presence of the Edelstein effect or not in mentioned materials.

The hyperfine interaction between carrier spins and nuclear spins is an important component in exploring spin-dependent properties in materials with strong spin orbit interaction.However hyperfine interaction has been less studied in bismuth (Bi), a heavy element exhibiting a strong Rashba-like spin-orbit interaction in its two-dimensional surface states due to the broken spatial inversion symmetry. In this dissertation we experimentally explore the carrier spin polarization due to transport under strong spin-orbit interaction and the nuclear polarization resulting from the relatively unexplored hyperfine interaction on Bi(111) films.The carrier and nuclear spin polarizations are expected to dynamically interact, a topic with ramifications to other materials where surface states with noteworthy properties play a role.To achieve this goal, an optimized van der Waals epitaxy growth technique for Bi(111) on mica substrates was developed and used, resulting in flat Bi surfaces with large grain sizes and a layered step height of 0.39±0.015 nm, corresponding to one Bi(111) bilayer height. A comparison between Bi(111) films grown on three different substrates (mica, InSb(111)B, and Si(111)) is discussed, for which scanning electron microscopy and atomic force microscopy are applied to obtain the structural and morphological characteristics on the film surface. Magnetotransport measurements are carried out to extract the transport properties of theBi(111) films. Using the high quality Bi(111) film deposited on mica, we develop quantum magnetotransport techniques as delicate tools to study hyperfine interaction. The approach is based on measuring quantum corrections to the conductivity due to weak antilocalization, which depend on the coherence of the spin state of the carriers. The carrier spin polarization is generated by a strong DC current in the Bi(111) surface states (here called the Edelstein effect), which then induces dynamic nuclear polarization by hyperfine interaction. Quantum transport antilocalization measurements in the Bi(111) thin-films grown on mica indicate a suppression of antilocalization by the in-plane Overhauser field from the nuclear polarization, and allow for the quantification of the Overhauser field, which is shown to depend on both polarization duration and the DC current magnitude. Various delay times between the polarization and the measurement result in an exponential decay of the Overhauser field, driven by relaxation time T1. We observe that in the Bi surface states, the appreciable electron density and strong spin-orbit interaction allow for dynamic nuclear polarization in the absence of an external magnetic field. / Doctor of Philosophy / This dissertation focuses on the heavy element bismuth (Bi), a semimetal with strong spin-orbit interaction at its two-dimensional surface. Given the challenge to grow high qualityBi(111) films, we present an optimized van der Waals epitaxy technique to grow Bi(111)films on mica substrates, which show a flat surface with large grain sizes and a layered step height of 0.391±0.015 nm, corresponding to one Bi(111) bilayer height. To demonstrate the high quality of the Bi(111) surface, a comparison of surface morphology was conducted among Bi(111) films deposited on three different substrates (mica, Si(111), and InSb(111)B),along with a comparison between their electronic transport properties. By applying a DC current on the high quality Bi(111) film on mica, a carrier spin polarization is established via mainly what we here call the Edelstein effect, which then induces dynamic nuclear polarization by hyperfine interaction and generates a non-equilibrium nuclear spin polarization without externally applied magnetic field. We quantified the Overhauser field from the nuclear polarization all-electrically by conducting quantum transport antilocalization experiments, which showed a suppression of antilocalization by the in-plane Overhauser field.Comparative measurements indicated that the magnitude of the Overhauser field depends onthe spin-polarizing DC current magnitude and the polarization duration. The experiments also show that antilocalization forms a sensitive probe for hyperfine interaction and nuclear polarization.

Diese Examensarbeit vergleicht zwei phantastische Jugendbücher aus dem Bereich der Romantic Fantasy (Romantasy) und analysiert inwiefern diese als Entwicklungsromane gelten. Die Trilogien sind die Edelstein Trilogie von Kerstin Gier und die Zeit Trilogie von Sandra Regnier. Der erste Abschnitt definiert und zeigt die Merkmale und Muster von Entwicklungsromanen, Fantasy und Romantasy auf. Der zweite Teil analysiert beide Trilogien auf ihre dargestellten Konflikte, die die Protagonisten bewältigen müssen und deren erfolgten Entwicklungsprozess. Es wird gezeigt wie phantastische Aspekte den Entwicklungsprozess beeinflussen und wo sich Merkmale des Entwicklungsromans in moderner Jugendbuchliteratur wiederfinden lassen.

The gemological collection of Abraham Gottlob Werner contains 1374 sample numbers for 25 different minerals with 38 gemological varieties, including 15 newly added numbers of samples, which were not recorded in the original catalog of 1823. In total, 168 samples were recorded as lost by the later researchers, 4 samples were taken for the chain for the rector of the university, samples of 2 different numbers in the catalog were exchanged for cut stones, and 3 times’ volume requisitions happened. A total of 256 sample numbers show discrepancies and therefore are not in accordance with the original record in the catalog. In the collection, 6.8% of the numbers are rock sample with embedded crystals, 20.7% of the numbers are in the form of crystal, 30.6% of the numbers are fragments, 11.6% of the numbers are grains, and the remaining 711 samples are cut. Except for Esa. No. 644a containing four cushion cut samples, all faceted cuts were recorded in the original catalog of 1823. However, the brilliant, oval, step, emerald, scissor, and radiant cut forms were invented after the gemological collection of Werner, which means 189 samples do probably not belong to the original collection. They could be from another collection due to the requisitions, or the later researchers of the collection added or exchanged the samples with new ones. The mineral names of the catalog from 1823 refer to Werner's mineral system, some of the mineral's names are not used anymore. With the development of mineralogy and gemology, the special names of the gemstones as varieties of minerals are gradually standardized. 51 samples are wrong identifications and 8 pieces of glass have been recognized. The zircon samples of the collection provide a research resource for the study of metamictization. Both color and density of zircon could be an indicator of the metamictization degree. The metamictization has a significant influence on the gemological properties of zircon. The green tone and low density cannot be considered as an identifying characteristic of metamict zircon, although they are still a sign of metamictization. Comparing six mineralogical or geological collections at Werner’s time, the catalogs of five collections used his nomenclature of samples and only the catalog of the mineralogical collection of Adolf Traugott von Gersdorf is geographical. To his time the outstanding gemological collection of Abraham Gottlob Werner represented the broadest quantity of gemological varieties. A modern gemological database of the collection has been founded, the meta-data provides an important base for further research and development.:Acknowledgements I Abstract III Table of Contexts IV List of figures VI List of tables VII 1. Introduction 1 1.1 Abraham Gottlob Werner 1 1.2 The mineral system of Werner 1 1.3 The gemological collection of Werner 3 2. Methods 6 2.1 Specific gravity (SG) measurements 6 2.1.1 Hydrostatic weighing 6 2.1.2 He-pycnometer 6 2.2 Color 6 2.2.1 Munsell color system 7 2.2.2 The CIE L*C*h color system 8 2.3 The optical measurements 9 2.3.1 Polariscope 9 2.3.2 Refractometer 10 2.3.3 Dichroscope 11 2.4 Ultraviolet (UV) fluorescence test 12 2.5 Raman spectroscopy 12 3. New model for the inventory of the gemological collection of Werner 13 4. Discussion 16 4.1 Cut cutting in the course of time 16 4.2 Classification of gemstones 24 4.2.1 Individual names of gemstones 25 4.2.2 Different identifications with the catalog of 1823 29 4.2.3 Imitation of gemstones 31 4.3 Raman spectrum study of zircons 32 4.4 Comparison of the outstanding Werner Collection with other collections in the second half of 18th century 39 4.4.1 The natural history collection of Linck family (1638-1807) 39 4.4.2 The Minerals cabinet of Eugen Pabst von Ohain (1718-1784) 40 4.4.3 The natural history collection of the University of Rostock 40 4.4.4 The mineralogical collection of Adolf Traugott von Gersdorf (1744-1807) 41 4.4.5 The mineralogical, geological and paleontological collection of Johann Wolfgang von Goethe (1749-1832) 42 4.4.6 Summary of the additional collections to Werner's time 43 5. Summary 44 Reference 46 Appendix A 59 Appendix B 63 Appendix C 67

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