Preparation of atoms in a triangular optical lattice with high filling fraction

An optical lattice filled with one atom per site is an ideal starting point for quantum simulation and quantum information control. In the Quantum Matter Synthesizer (QMS) apparatus, we prepare and perform site-resolved imaging of individual cesium atoms in a triangular optical lattice. We observe that a high lattice filling fraction in excess of 70% can be prepared by introducing a blue-detuned optical pumping beam. The beam induces strong repulsion between atoms when two or more of them are loaded into a single lattice site. Using a statistical model, we show that when the on-site repulsion exceeds the thermal energy, it can lead to the emergence of a Mott insulating state in the optical lattice.