Abstract

16.1.18 Dr. Philipp Preiss Tuesday, 3:30pm, RUTHERFORD Seminar room Heidelberg University, Germany

Ultracold quantum gases in optical potentials have achieved spectacular progress in the experimental simulation of complex quantum systems. Complementary to many-body experiments, mesoscopic systems comprised of a small number of atoms offer the possibility to study entangled quantum states with an exceptional degree of versatility and control. We have implemented a highly tunable platform to study such correlated few-fermion systems. Using reconfigurable optical microtraps, we prepare quantum states of 6Li atoms with a deterministic atom number and spin configuration and tune interactions via a magnetic Feshbach resonance. A novel readout scheme with single-particle sensitivity allows us to measure spin-resolved correlation functions in position and in momentum space. Such correlators characterize few-body systems via the coherence and symmetry of the wavefunction. Focusing on the Fermi-Hubbard double-well, we observe high-contrast interference of indistinguishable fermions, the build-up of correlations due to interactions, and the emergence of entanglement between particles. Our techniques can be applied to larger systems to characterize many-body phases via their higher-order correlation functions.