Novel physics of polar molecules in optical lattices

偶极-偶极相互作用的远距离各向异性特征导致了偶极气体中丰富的新物理学，最近在原子磁偶极子上的实验已经部分揭示了这一点。最近对异核分子的实验使我们能够预见到未来极性分子的量子简并气体。与相对弱的原子磁偶极子相反，极性分子的电偶极矩可能非常大，如果适当地由外电场定向，电偶极子-偶极子相互作用可能完全支配系统。这对于深光学晶格中的极性分子来说可能是特别引人注目的，在那里，偶极-偶极相互作用允许分子在不同位置的强相互作用，即使没有跳跃。这一建议侧重于这种位点间耦合引入的新效应。弱偶极子可能导致位点间杂化激励，增强不稳定性。更令人着迷的是，强偶极子可以诱导位于不同位置的粒子组成复合物。我们特别计划研究双阱势下玻色和费米气体中的对超流动性和类bcs配对。本课题将通过研究极性分子的细丝，以及细丝的理想气体和相互作用气体的物理特性来完成。

The long-range anisotropic character of the dipole-dipole interaction leads to a wealth of new physics in dipolar gases, already partially unveiled by recent experiments on atomic magnetic dipoles. Recent experiments on heteronuclear molecules allow to foreseeing a quantum degenerate gas of polar molecules in the next future. Contrary to the relatively weak atomic magnetic dipoles, the electric dipole moment of polar molecules may be extraordinarily large, and if properly oriented by an external electric field, the electric dipole-dipole interaction may completely dominate the system. This may be particularly striking for polar molecules in deep optical lattices, where the dipole-dipole interaction allows for a strong interaction of molecules at different sites even without hopping. This proposal focuses on the novel effects introduced by this inter-site coupling. Weak dipoles may lead to inter-site hybrid excitations, and the enhancement of instabilities. Even more fascinatingly, strong dipoles may induce the formation of composites of particles lying at different sites. We plan in particular the study of pair-superfluidity and BCS-like pairing in Bose and Fermi gases in two-well potentials. The project will be completed by the study of filaments of polar molecules, and the physics of ideal and interacting gases of filaments.