Dokument: A new RbYb ultracold mixture machine – from room temperature to 2-photon-photoassociation on the intercombination line

Titel:	A new RbYb ultracold mixture machine – from room temperature to 2-photon-photoassociation on the intercombination line
URL für Lesezeichen:	https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=62725
URN (NBN):	urn:nbn:de:hbz:061-20230612-104105-7
Kollektion:	Dissertationen
Sprache:	Englisch
Dokumententyp:	Wissenschaftliche Abschlussarbeiten » Dissertation
Medientyp:	Text
Autor:	Franzen, Tobias [Autor]
Dateien:	[Dateien anzeigen] Adobe PDF [Details] 10,24 MB in einer Datei [ZIP-Datei erzeugen] Dateien vom 23.05.2023 / geändert 23.05.2023
Beitragende:	Prof. Dr. Görlitz, Axel [Gutachter] Prof. Dr. Schiller, Stephan [Gutachter]
Dewey Dezimal-Klassifikation:	500 Naturwissenschaften und Mathematik » 530 Physik
Beschreibung:	In the scope of this thesis, an apparatus for the stable and reliable production of ultracold mixtures of Rb and Yb has been developed and demonstrated. Due to the use of long distance optical transport, many of the cooling steps for each species can be performed in separate vacuum chambers, allowing them to be performed in parallel and vastly improving optical access to both the production and the science chamber. The separation will allow the reconfiguration of the science chamber for further experiments, for example by installing electrodes or high-field magnetic coils, without breaking vacuum in the production chambers. Bose-Einstein condensation of each species was demonstrated and ultracold thermal mixtures of both species are routinely produced. The achieved densities compare favorably with those in previous experiments while several hours of hands off operation now allow for extensive spectroscopy to be performed. A variety of optical traps including an optical lattice allow experiments to be performed under a variety of trapping conditions. Several laser systems with precise, tuneable frequency stabilisation near the narrow 1S0- 3P1 intercombination line of Yb were implemented – among them a novel fiber amplifier design – and used for several photoassociation experiments. Homonuclear 170Yb2 photoassociation resonances up to a binding energy of h · 10.7 GHz were measured, extending the range by an order of magnitude compared to the previously known lines in 170Yb and by a factor of five compared to the other more extensively explored isotopes. Although the physics of the Yb dimer are interesting in their own right, these investigations primarily laid the groundwork for the next step. Working towards the long standing goal of the production of ground state RbYb molecules, extensive photoassociation spectroscopy was performed in a mixture of 87Rb and 170Yb over detunings ranging from 0.1 GHz to 11 GHz. This search yielded a single pair of resonances around 3 GHz detuning. To the best of the authors knowledge this is the first time the narrow intercombination line transition of Yb has been used for photoassociation of an Yb-alkali dimer. Relevant shift mechanisms were investigated and the corresponding binding energies were determined to be h · 3057.0(5) MHz and h · 3074.1(5) MHz. The photoassociation rate constant was measured to be K_PA ≈ 5e−14 cm^3/s under the current conditions and paths for further improvement were identified, for example through use of an optical lattice. Building on these results, the technique of two-photon photoassociation was used to obtain binding energies for the two most weakly bound vibrational states of the electronic ground state as E_B (∆ν′ = −1) = h · 101.9(1) MHz and E_B (∆ν′ = −2) = h · 1011.0(1) MHz, with a precision two orders of magnitude higher than that of previous measurements. This sensitive probe paves the way for further investigations of the 2Σ ground state of the RbYb molecule and will be invaluable in future spectroscopy. Furthermore, the observation of dark resonances involving these states indicates a successful coherent coupling between atoms and molecules, potentially enabling the coherent photoassociation by free-bound STIRAP in the future. Finally, various improvements to the apparatus have been suggested. Various topics for further investigations have been pointed out and the path towards production of RbYb molecules in the absolute ground state has been outlined.
Lizenz:	Urheberrechtsschutz
Fachbereich / Einrichtung:	Mathematisch- Naturwissenschaftliche Fakultät » WE Physik » Experimentalphysik
Dokument erstellt am:	12.06.2023
Dateien geändert am:	12.06.2023
Promotionsantrag am:	22.12.0022
Datum der Promotion:	11.04.0023