Preparing low-entropy Fermi-Hubbard systems with direct laser cooling

In recent years, few-particle systems of ultracold atoms have emerged as a viable tool for exploring strongly correlated quantum systems [1]. They allow to pursue a bottom-up approach by deterministically preparing small ground-state quantum systems and then using them as building blocks for assembling larger systems. Here we present a new experiment aimed at using Raman sideband cooling of $^{40}$K atoms in optical tweezers to prepare few-site Fermi-Hubbard systems with sub-second cycle times and probe them with single-site resolution [2]. \vspace{0.5 cm} \\ {[1] S. Murmann, A. Bergschneider, V. M. Klinkhamer, G. Z\"urn, T. Lompe, S. Jochim, Two Fermions in a Double Well: Exploring a Fundamental Building Block of the Hubbard Model, Phys. Rev. Lett. {\bf{114}}, 080402 (2015)} \\ {[2] L. W. Cheuk, M. A. Nichols, M. Okan, T. Gersdorf, V. V. Ramasesh, W. S. Bakr, T. Lompe, and M. W. Zwierlein, Quantum-Gas Microscope for Fermionic Atoms, Phys. Rev. Lett. {\bf{114}}, 193001 (2015)}