Quantum dynamics of strongly correlated RbCs dipolar quantum gases

局限于晶格势的超冷原子和分子为强关联量子多体系统的可控制备和研究提供了无数的可能性。对于原子，该领域的里程碑是凝聚态物理学哈伯德模型的实验实现和局部接触相互作用系统的超流体到莫特绝缘体相变的观察。分子有潜力极大地拓宽可以研究的强关联量子系统的光谱。特别地，具有长程和取向依赖的电偶极-偶极相互作用的偶极分子提供了新的机会来探测例如新形式的超流性和有趣的多体基态（例如偶极晶体、超固体、分数莫特绝缘体、量子磁体等）与新颖的量子相变相结合，本项目旨在研究超冷RbCs偶极玻色子在一维和二维几何和晶格势中的动力学。的RbCs偶极子，最初从原子对位于高填充率的光学晶格的各个站点制备，将在冻结自旋（即在晶格中的固定空间位置）的制度和移动的偶极子的制度进行研究。我们将探索在多大程度上可以实现新的多体自旋模型，可能应用于量子模拟领域，并研究由量子偶极子组成的多体系统的稳定性，动力学和弛豫过程局限于低维几何。特别是，我们的项目的目的是在实验中测试的动态过程所允许的扩展哈伯德模型，即哈伯德模型增强的条款建模场外交互条款。该项目基于现有的Rb-Cs量子气体混合物装置（在FWF资助的奥地利SFB FoQuS内建立了几年），我们已经实现了超冷RbCs分子到RbCs基态分子的特定超精细子能级的有效基态转移，并且我们已经证明了三维晶格势中的高分子填充分数。

Ultracold atoms and molecules confined to lattice potentials offer myriad possibilities for the controlled preparation and study of strongly correlated quantum many-body systems. For atoms, milestones in the field have been the experimental realization of the Hubbard model of condensed matter physics and the observation of the superfluid-to-Mott-insulator phase transition for systems with local contact interactions. Molecules have the potential to greatly broaden the spectrum of strongly correlated quantum systems that can be investigated. In particular, dipolar molecules with their long-range and orientation dependent electric dipole-dipole interaction provide new opportunities to probe e.g. novel forms of superfluidity and interesting many-body ground states (such as dipolar crystals, supersolids, fractional Mott insulators, quantum magnets,…) in conjunction with novel quantum phase transitions, and in general non-equilibrium quantum many-body dynamics.This project is aimed at studying the dynamics of ultracold RbCs dipolar bosons confined to one- and two-dimensional geometry and lattice potentials. The RbCs dipoles, initially prepared from atom pairs located at individual sites of an optical lattice at high filling fraction, will be studied in the regimes of frozen spins (i.e. fixed spatial location in the lattice) and in the regime of mobile dipoles. We will explore to what extent one can realize novel many-body spin models, with possible applications to the field of quantum simulation, and study the stability, dynamics and relaxation processes for many-body systems composed of quantum dipoles confined to low-dimensional geometry. In particular, our project aims at testing in experiments the dynamical processes as allowed by the extended Hubbard model, i.e. the Hubbard model augmented by terms modeling off-site interaction terms. The project is based on an existing Rb-Cs quantum gas mixture apparatus (set up over several years within the Austrian SFB FoQuS, funded by the FWF) for which we have implemented efficient ground-state transfer of ultracold RbCs molecules into a specific hyperfine sublevel of the RbCs ground-state molecule and for which we have demonstrated high molecular filling fraction in a three-dimensional lattice potential.