Spatial coherence of a strongly interacting Bose gas in the trimerized kagome lattice

Abstract

We produce a trimerized kagome lattice for ultracold atoms using an optical superlattice formed by overlaying triangular lattices generated with two colors of light at a 2:1 wavelength ratio. Adjusting the depth of each lattice tunes the strong intratrimer ($J$) and weak intertrimer (${J}^{\ensuremath{'}}$) tunneling energies, and also the on-site interaction energy $U$. Two different trimerization patterns are distinguished using matter-wave diffraction. We characterize the coherence of a strongly interacting Bose gas in this lattice, observing persistent nearest-neighbor spatial coherence in the large $U/{J}^{\ensuremath{'}}$ limit, and that such coherence displays asymmetry between the strongly and the weakly coupled bonds.