Quantum control of ultracold polar molecules

一种排列成规则阵列的极冷分子气体将成为强相互作用量子系统的理想量子模拟器。这个项目将专注于创建这个系统，从磁光阱捕获的分子开始。该项目的第一部分是研究分子磁光阱中的亚多普勒冷却过程，并利用这些过程将分子冷却到亚毫开尔文的温度。下一步将是研究在超冷温度下原子和分子之间的碰撞。这将通过将冷分子云与超冷原子云重叠来实现，首先在磁光阱中，然后在磁阱中，最后在微波阱中。目前关于这些极低温度下的弹性和非弹性碰撞过程的信息很少，因此这项研究将产生丰富的新知识。利用这项研究的结果，我们将同情地用原子冷却分子。通过驱动蒸发冷却过程，原子可以冷却到亚微开尔文温度，同时通过弹性碰撞使分子与原子保持热平衡。这提供了一条通往由极冷分子组成的致密气体的途径。最后，将使用光镊陷阱捕获气体中的单个分子，并研究单个分子和分子对的相干操作。

A gas of ultracold polar molecules, arranged as a regular array, will make an ideal quantum simulator of strongly-interacting quantum systems. This project will focus on creating this system, starting from molecules captured in a magneto-optical trap. The first part of the project is to investigate sub-Doppler cooling processes in the molecular magneto-optical trap and use these to cool the molecules to sub-milliKelvin temperatures. The next step will be to investigate collisions between atoms and molecules at ultracold temperatures. This will be done by overlapping a cloud of cold molecules with a cloud of ultracold atoms, first in a magneto-optical trap, then in a magnetic trap, and finally in a microwave trap. There is currently very little information about elastic and inelastic collisional processes at these very low temperatures, so this investigation will yield a wealth of new knowledge. Using the results of this study, we will sympathetically cool the molecules using the atoms. By driving an evaporative cooling process, the atoms can be cooled to sub-micro-Kelvin temperatures while keeping the molecules in thermal equilibrium with the atoms through elastic collisions. This provides a route to a dense gas of ultracold polar molecules. Finally, single molecules from this gas will be captured using optical tweezer traps, and the coherent manipulation of individual molecules and molecule pairs will be investigated.