Tunable Superfluidity and Quantum Magnetism with Ultracold Polar Molecules

• Main Authors: Gorshkov, Alexey V, Manmana, Salvatore R, Chen, Gang, Ye, Jun, Demler, Eugene, Lukin, Mikhail D, Rey, Ana M
• Format: Report
• Language: English
• Subjects: Atomic and Molecular Physics and Spectroscopy; ATOMS; LONG RANGE(DISTANCE); MAGNETIC PROPERTIES; MOLECULES; OPTICAL PROPERTIES; OSCILLATION; PHASE DIAGRAMS; QUANTUM THEORY; REPRINTS; SUPERFLUIDITY

By selecting two dressed rotational states of ultracold polar molecules in an optical lattice, we obtain a highly tunable generalization of the t-J model, which we refer to as the t-J-V-W model. In addition to XXZ spin exchange, the model features density-density interactions and density-spin interactions; all interactions are dipolar. We show that full control of all interaction parameters in both magnitude and sign can be achieved independently of each other and of the tunneling. As a first step towards demonstrating the potential of the system, we apply the density matrix renormalization group method to obtain the 1D phase diagram of the simplest experimentally realizable case. Specifically, we show that the tunability and the long-range nature of the interactions in the t-J-V-W model enable enhanced superfluidity. Finally, we show that Bloch oscillations in a tilted lattice can be used to probe the phase diagram experimentally. Published in Physical Review Letters, v107 p115301-1/115301-5, 9 September 2011.