Dokument: Preparation, Manipulation, and Spectroscopy of Cold Trapped Beryllium Ions and Molecular Hydrogen Ions
| Titel: | Preparation, Manipulation, and Spectroscopy of Cold Trapped Beryllium Ions and Molecular Hydrogen Ions | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=61176 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20221111-114640-6 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | Shen, Jianwei [Autor] | |||||||
| Dateien: |
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| Beitragende: | Prof. Dr. Schiller, Stephan [Gutachter] Prof. Dr. Büscher, Markus [Gutachter] | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 530 Physik | |||||||
| Beschreibung: | This work presents various results and applications in the field of cold atoms and molecules, with the aim of high-resolution spectroscopy of the molecular hydrogen ion HD+. By adjusting the frequencies of the cooling and repumping laser, the process of Coulomb crystallization of a beryllium ensemble was studied.
Precise spectroscopy of cold atoms and molecules requires understanding and controlling the local magnetic field. For this purpose, based on a large number of Raman spectroscopic measurements of Be+ ions, the conditions of the zero magnetic field, as well as the relations between the magnetic fields and the currents of Helmholtz coils in all three dimensions, have been found. Based on this work, excitation of the fundamental rotational transition of HD+ at 1.3 THz by using two experimental methods was performed, and significant transition frequencies were recorded. In addition, the BBR-induced rotational excitation was also observed. It is indicated from the obtained spectra that the Lamb-Dicke regime was reached and the Zeeman effect was successfully observed, from which, an upper limit of the magnetic field in the trap center of 1.5 G was estimated. It is for the first time to clearly detect the fundamental rotational transition of HD+ by terahertz radiation, which is of the utmost importance, since it is the most fundamental dipole-allowed rotational transition of any molecule, and has not been observed before. For the purpose of QCL hyperfine pumping that can be applied in the HD+ project, a so-called transfer cavity system that couples the QCL with a DFB laser was developed. In this system, the QCL was frequency stabilized to the cavity, while the latter was locked to the DFB laser. Thus, by means of adjusting the frequency of the DFB laser, the related QCL frequency could be controlled correspondingly. For demonstration of the application of the transfer cavity system, by together applying a frequency-tunable OPO, the QCL was used as a hyperfine pumping source to drive the corresponding weak transitions of HD+. Thus, the quantum state preparation to a specific hyperfine state of HD+ has been realized. Subsequently, the doubly-spin-forbidden transition of HD+ was detected as well. Through these experiments, it reveals the importance of the quantum state preparation for high-resolution spectroscopy. It is useful to consider the extension of this work to other atomic and molecular species. | |||||||
| Lizenz: |  Dieses Werk ist lizenziert unter einer Creative Commons Namensnennung 4.0 International Lizenz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Physik » Experimentalphysik | |||||||
| Dokument erstellt am: | 11.11.2022 | |||||||
| Dateien geändert am: | 11.11.2022 | |||||||
| Promotionsantrag am: | 05.04.2022 | |||||||
| Datum der Promotion: | 04.10.2022 |
