A versatile ultracold strontium apparatus From construction to new tools for quantum simulation

The thesis describes the process of building a new ultracold strontium apparatus and developing new techniques paving the way to future research. The building process starts from empty optical tables and gradually moves through stages of designing, assembling and characterizing the new apparatus. These stages comprise constructing the vacuum system and attaining ultra-high vacuum, building the laser systems and implementing methods and techniques to bring the thermal atoms to quantum degeneracy. These methods include transverse cooling, Zeeman slowing, magneto-optical trapping on the broad and narrow transitions, dipole trapping and evaporative cooling to Bose-Einstein condensation and Fermi degeneracy. The prepared degenerate quantum gases are a foundation for future research, aiming at exploiting the unique properties of strontium for quantum simulations. To implement the quantum simulations of interest to us several additional experimental techniques are required and within this thesis two of these developments have been accomplished. The first one is measuring the frequency of the ultranarrow ¹S₀ - ³P₂ transition in fermionic strontium. This transition should allow nuclear spin-state specific Raman coupling or light shifting without much off-resonant scattering of photons, which is useful to implement artificial gauge fields or synthetic dimensions while keeping the system long-lived. The second development is the construction of a microscope objective for a high-resolution imaging system that allows the manipulation and detection of single atoms trapped in an optical lattice or in optical tweezers.