Stuttgart 2012 – wissenschaftliches Programm
Q 35.14: Poster
Mittwoch, 14. März 2012, 16:30–19:00, Poster.I+II
Shaking Optical Lattices: From Frustrated Magnetism to Synthetic Gauge Fields — •Christoph Ölschläger1, Julian Struck1, Malte Weinberg1, Juliette Simonet1, André Eckardt2, Patrick Windpassinger1, and Klaus Sengstock1 — 1Institut für Laserphysik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany — 2Max-Planck-Institut für Physik komplexer Systeme, Noethnitzer Strasse 38, 01187 Dresden, Germany
Ultracold quantum gases in optical lattices are well suited to investigate and simulate systems known from solid state physics.
Here we report on the experimental realization of frustrated classical magnetism in triangular optical lattices as well as tuneable artificial gauge fields in one-dimensional optical lattices with ultracold atoms. First, by applying a time-reversible, periodic force to spinless bosons, it is possible to change the order and sign of the tunneling matrix elements between adjacent lattice sites in a wide range. In a triangular optical lattice we observe different non-ferromagnetic phases that can be described in analogy to classical magnetism.
Second, by inducing a time-irreversible, periodic force, we present the possibility to create complex-valued tunneling matrix elements, where the resulting Peierls phase can be tuned between zero and two pi. With this we are able to realize a synthetic gauge field in a one dimensional optical lattice, which leads to the observation and analysis of ground state superfluids at arbitrary, finite quasi momentum. Extending these methods to triangular optical lattices, it is possible to create staggered magnetic fields with large fluxes per plaquette.