01573nas a2200181 4500008004100000245004700041210004700088260001400135490000700149520106900156100002501225700002701250700001501277700001901292700002301311700002001334856003701354 2011 eng d00aQuantum Magnetism with Polar Alkali Dimers0 aQuantum Magnetism with Polar Alkali Dimers c2011/9/150 v843 a We show that dipolar interactions between ultracold polar alkali dimers in
optical lattices can be used to realize a highly tunable generalization of the
t-J model, which we refer to as the t-J-V-W model. The model features
long-range spin-spin interactions J_z and J_perp of XXZ type, long-range
density-density interaction V, and long-range density-spin interaction W, all
of which can be controlled in both magnitude and sign independently of each
other and of the tunneling t. The "spin" is encoded in the rotational degree of
freedom of the molecules, while the interactions are controlled by applied
static electric and continuous-wave microwave fields. Furthermore, we show that
nuclear spins of the molecules can be used to implement an additional (orbital)
degree of freedom that is coupled to the original rotational degree of freedom
in a tunable way. The presented system is expected to exhibit exotic physics
and to provide insights into strongly correlated phenomena in condensed matter
systems. Realistic experimental imperfections are discussed.
1 aGorshkov, Alexey, V.1 aManmana, Salvatore, R.1 aChen, Gang1 aDemler, Eugene1 aLukin, Mikhail, D.1 aRey, Ana, Maria uhttp://arxiv.org/abs/1106.1655v101551nas a2200193 4500008004100000245008200041210006900123260001300192490000800205520096600213100002501179700002701204700001501231700001201246700001901258700002301277700002001300856003701320 2011 eng d00aTunable Superfluidity and Quantum Magnetism with Ultracold Polar Molecules
0 aTunable Superfluidity and Quantum Magnetism with Ultracold Polar c2011/9/80 v1073 a 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 novel 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 (DMRG) 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.
1 aGorshkov, Alexey, V.1 aManmana, Salvatore, R.1 aChen, Gang1 aYe, Jun1 aDemler, Eugene1 aLukin, Mikhail, D.1 aRey, Ana, Maria uhttp://arxiv.org/abs/1106.1644v1