Kurzfassung
SummarizeAbstract Zusammenfassung Contents Chapter 1 Introduction 1.1 Energy and length scales in ultracold systems 1.2 Quantum Simulation 1.3 Thesis Overview Chapter 2 Strontium in a nutshell 2.1 Atomic and nuclear characteristics 2.2 Energy levels scheme and optical transitions 2.3 Isotopes Interaction Properties Chapter 3 Experimental apparatus and blue MOT 3.1 Experimental apparatus overview manifestConstruction of a novel strontium quantum simulator Dissertation zur Erlangung des Doktorgrades an der Fakultät für Mathematik, Informatik und Naturwissenschaften Fachbereich Physik der Universität Hamburg vorgelegt von Meny Menashes Hamburg April 2025 Gutachter/innen der Dissertation: Prof. Dr. Ludwig Mathey Dr. Guillaume Salomon Zusammensetzung der Prüfungskommission: Prof. Dr. Ludwig Mathey Prof. Dr. Henning Moritz Prof. Dr. Ralf Riedinger Dr. Christoph Becker Dr. Guillaume Salomon Vorsitzende/r der Prüfungskommission: Prof. Dr. Ludwig Mathey Datum der Disputation: 13.05.2025 Vorsitzender des Fach-Promotionsausschusses PHYSIK: Prof. Dr. Markus Drescher Leiter des Fachbereichs PHYSIK: Prof. Dr. Wolfgang J. Parak Dekan der Fakultät MIN: Prof. Dr.-Ing. Norbert Ritter Acknowledgments When I moved to Germany at the end of 2021, I did not know the amount of effort it would take to build a machine of this capacity in three and a half years. Through that time, I have learn many new aspects of physics that were only known to me theoretically, and I have never designed and constructed them to be applicable for cooling and trapping atoms. This journey was full of new aspects of fundamental experimental physics, building tools that are now being used in our laboratory. For these reasons, I would like to thank first my supervisor, Guillaume Salomon, who showed me how experimental work is done and contributed to my understanding of the physics of ultracold atoms and particularly strontium. I am sincerely grateful for his thorough review of my thesis and his valuable input on my writing. Although crafting the dissertation was challenging for me, I am sure that carefully examining every aspect was not easy for him either. I would like to thank Henning Moritz, who, almost four years ago, responded to my email and gave me the opportunity to leave my country and travel to Hamburg. It was a great honor to have discussions with him that were not always physicsrelated but helped me profoundly. I want to thank my dear colleague Leon Schäfer, with whom I shared an office and who helped me with german language barriers when I could not understand specific terms. To my other colleague Thies Plaßmann, who is doing an amazing job holding the lab together, and I admire his work ethic, coming over the weekend to do measurements at the same time I was writing my thesis. I thank Cesar Cabrera, with whom I had many a fruitful discussion and was able to explain things to me in the most basic way possible. To Benjamin Abeln, Jose Antonio Vargas, Rene Henke, and Hauke Biss, I thank you for helping me with my corrections on the thesis and for giving me feedback when I needed. I want to thank the entire support of the CUI, especially Jutta Voigtmann, who gave me a bit more air to breathe and was very understanding of my situation last year. I would like to thank the support of the workshop and Stephan Fleig, as well as the purchasing department, with Melanie Grundner. Both of them assisted me when it came to building new elements and ordering parts for our experiment. Finally, I would like to thank my family, my mom, dad, and sister Hanna, David, and Maayan, for their support, and to Alina, thank you for being there for me with love and care. Abstract This thesis details the design and construction of a novel quantum simulator platform using ultracold strontium atoms. We establish key experimental infrastructure—including a high-flux atomic source, an ultra-high vacuum environment, and a cost-effective laser delivery system—to manipulate strontium’s internal degrees of freedom. These techniques were developed for cooling and trapping all four stable isotopes, enabling diverse investigations into both bosonic and fermionic physics. Our experimental approach begins with a blue magneto-optical trap (MOT) operating on the broad 1S0 → 1P1 transition at 461 nm, which efficiently captures and cools thermal atoms from a strontium oven. The atoms are subsequently transferred to a red MOT based on the narrow intercombination line at 689 nm, where precise frequency modulation and spectral broadening techniques allow us to achieve temperatures below 1 µK. Central to the simulator’s capabilities is the integration of a 3D accordion lattice that provides dynamic control over lattice spacing. The lattice in the vertical gravity direction design and construction is described to give an overview of its confinement efficiency. Specifically, the realization of a 2D trap is needed to study spin models in reduced dimensionality. Our approach involves a single-atom imaging setup enabled by a high numerical aperture objective microscope and a single-photon camera. This platform allows us to probe many-body phenomena at the single-atom level. To accommodate spin detection with our microscope, we introduce an optical Stern-Gerlach scheme to spatially resolve the atomic nuclear spin during free-fall. This technique can help engineer a spin-dependent potential and leverage the SU(N > 2) symmetry of 87Sr for exploring the interplay between magnetism and interactions within a Fermi-Hubbard model framework. Zusammenfassung Diese Dissertation beschreibt das Design und den Aufbau einer neuartigen Plattform für Quantensimulationen mit ultrakalten Strontiumatomen. Wir entwickeln zentrale experimentelle Komponenten – einschließlich einer Hochfluss-Atomquelle, eines Ultrahochvakuum-Systems und einer kosteneffizienten Laserstrahlführung – um die inneren Freiheitsgrade von Strontium gezielt zu kontrollieren. Die entwickelten Methoden ermöglichen das Kühlen und Einfangen aller vier stabilen Isotope und eröffnen damit vielseitige Untersuchungen sowohl in der bosonischen als auch in der fermionischen Physik. Der experimentelle Ablauf beginnt mit einer blauen magneto-optischen Falle (MOT), die auf dem breiten Übergang 1S0 → 1P1 bei 461 nm basiert und thermische Atome effizient aus einem Strontiumofen einfängt und vorkühlt. Anschließend erfolgt die Überführung in eine rote MOT auf der schmalen Zwischenzustandslinie bei 689 nm. Durch präzise Frequenzmodulation und spektrale Verbreiterung werden Temperaturen unterhalb von 1 µK erreicht. Ein zentrales Element des Simulators ist die Integration eines dreidimensionalen „Accordion“Gitters, das eine dynamische Kontrolle des Gitterabstands erlaubt. Der Aufbau und die Konstruktion des vertikalen Gitters entlang der Gravitationsrichtung werden beschrieben, um die Effizienz der Einschlussbedingungen darzustellen. Insbesondere ist die Realisierung einer zweidimensionalen Falle entscheidend, um Spinmodelle in reduzierter Dimensionalität zu untersuchen. Unser Ansatz umfasst ein Einzelatom-Bildgebungssystem, bestehend aus einem Große NA-Objektivmikroskop und einer Einzelphotonenkamera. Diese Plattform ermöglicht es, Vielteilchenphänomene auf der Ebene einzelner Atome zu untersuchen. Um die Spindetektion mit dem Mikroskop zu ermöglichen, führen wir ein optisches SternGerlach-Verfahren ein, das die räumliche Aufspaltung des nuklearen Spins während des freien Falls erlaubt. Diese Technik kann dazu verwendet werden, spinabhängige Potentiale zu erzeugen und die SU(N > 2)-Symmetrie von 87Sr auszunutzen, um das Zusammenspiel von Magnetismus und Wechselwirkungen im Rahmen des Fermi-Hubbard-Modells zu erforschen.
This thesis details the design and construction of a novel quantum simulator platform using ultracold strontium atoms. We establish key experimental infrastructure—including a high-flux atomic source, an ultra-high vacuum environment, and a cost-effective laser delivery system—to manipulate strontium’s internal degrees of freedom. These techniques were developed for cooling and trapping all four stable isotopes, enabling diverse investigations into both bosonic and fermionic physics. Our experimental approach begins with a blue magneto-optical trap (MOT) operating on the broad 1S0 → 1P1 transition at 461 nm, which efficiently captures and cools thermal atoms from a strontium oven. The atoms are subsequently transferred to a red MOT based on the narrow intercombination line at 689 nm, where precise frequency modulation and spectral broadening techniques allow us to achieve temperatures below 1 µK. Central to the simulator’s capabilities is the integration of a 3D accordion lattice that provides dynamic control over lattice spacing. The lattice in the vertical gravity direction design and construction is described to give an overview of its confinement efficiency. Specifically, the realization of a 2D trap is needed to study spin models in reduced dimensionality. Our approach involves a single-atom imaging setup enabled by a high numerical aperture objective microscope and a single-photon camera. This platform allows us to probe many-body phenomena at the single-atom level. To accommodate spin detection with our microscope, we introduce an optical Stern-Gerlach scheme to spatially resolve the atomic nuclear spin during free-fall. This technique can help engineer a spin-dependent potential and leverage the SU(N > 2) symmetry of 87Sr for exploring the interplay between magnetism and interactions within a Fermi-Hubbard model framework.