Feshbach resonances between a single ion and ultracold atoms

Abstract: Controlling physical systems and their dynamics on the level of individual quanta is key to propelling both fundamental science and quantum technologies. Trapped atomic and molecular systems, neutral and ionic, are at the forefront of quantum science due to their extraordinary level of control evidenced by numerous applications in quantum information processing and quantum metrology. Recently, the combination of these systems when merged in a hybrid atom-ion trap has gained interest in the atomic community. Here, hybrid atom-ion systems combine conventional radio-frequency (rf) traps for the ion with optical dipole traps for the atoms. Unfortunately, the presence of oscillating rf fields limits a majority of these experiments to collision energies on the order of a few milli-Kelvin. Although these experiments lead to landmark results in the classical regime, reaching ultracold temperatures, where quantum mechanics dominates the interaction and allows access to controllable scattering resonances, such as Feshbach resonances, has been elusive so far. In this thesis, we report on the first observation of Feshbach resonances between a single ion and a gas of ultracold atoms. Here, we make use of a mixture with large mass imbalance - 138Ba+ ions and 6Li atoms - which has recently been predicted to be suitable to reach the quantum mechanical few-partial wave regime despite the presence of rf fields. On our way towards magnetically tunable Feshbach resonances, we introduce several technical advancements, including a precise control over stray electric fields down to 3 mV/m and a novel approach for deterministic single-ion preparation. Operating with a single ion we investigate various chemical reactions channels between the ion and the atomic ensemble. Preparing both the ion and the atoms in their respective electronic ground state we find the system to remain stable up to 1000 collisions. The latter is critical for performing sympathetic cooling towards ultracold energies. Entering the quantum regime, we vary the experimental parameters to probe different interaction processes. First, we enhance three-body reactions and the related losses to identify a total of 11 atom-ion Feshbach resonances. Second, we reduce the atomic density to make two-body interactions dominant and to improve the ion’s sympathetic cooling in the ultracold atomic bath. Our results provide deeper insights into atom-ion interactions, giving access to complex many-body systems and applications in experimental quantum simulation

Angaben zum Objekt

• Standort: Deutsche Nationalbibliothek Frankfurt am Main
• Umfang: Online-Ressource
• Sprache: Englisch
• Anmerkungen: Universität Freiburg, Dissertation, 2021

Klassifikation und Themen

• Schlagwort: Atoms ; Lithium ; Paul-Falle ; Dipolfalle ; Hybrides System ; Ion-Atom-Wechselwirkung ; Feshbach-Resonanz ; Streuung ; Streulänge ; Quantengas ; Quantentechnologie ; Quantenmechanisches System ; Quantensimulator ; Coulomb-Wechselwirkung ; Bariumion ; Lithiumatom ; Barium ; Lithium ; Laser

Beteiligte, Orts- und Zeitangaben

• Ereignis: Veröffentlichung
• (wo): Freiburg
• (wer): Universität
• (wann): 2021
• Urheber: Weckesser, Pascal
• Beteiligte Personen und Organisationen: Schätz, Tobias ; Albert-Ludwigs-Universität Freiburg. Fakultät für Mathematik und Physik

Weitere Informationen

• DOI: 10.6094/UNIFR/222424
• URN: urn:nbn:de:bsz:25-freidok-2224242
• Rechteinformation: Kein Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Letzte Aktualisierung: 25.03.2025, 13:42 MEZ