Group Seminar at LMU: Quantum simulation in the eight-fold optical quasicrystal lattice
David Gröters, University of Cambridge, UK
Group seminar at LMU Seminar Room & Zoom
Tuesday, March 26, 09:00 am (MEZ)
Abstract: Quasicrystals constitute a unique class of materials that exhibit rotational symmetries that are forbidden in typical periodic latices. This leads to a crystal structure which is not periodic yet longrange ordered and thus commonly referred to as quasidisordered. Disordered systems are known to host localized phases of matter in which transport and thermalization can be inhibited due to destructive interference effects like in the well-known Anderson Insulator. Similarly, interacting particles in quasicrystalline latices show an additional incoherent, yet compressible phase the Bose Glass which can be understood as the ground state limit of a more general many-body localized phase that is hypothesized at higher energies. We experimentally investigate the behaviour of bosonic 39K atoms in the eight-fold rotationally symmetric optical quasicrystal by testing the ground-state phase diagram, where we report the first experimental observation of the Bose Glass phase as well as test the superfluid phase and Mott insulating regime. Furthermore, we demonstrate the non-ergodic nature of the localized phase by showing that once a system has crossed the Bose Glass transition, the lost coherence cannot be restored. Finally, we probe out-of-equilibrium dynamics such as quenching the superfluid-Bose Glass transition and directly observing atom localization in transport measurements.