Quantum Simulation in Synthetic Dimensions using Ultracold Molecules

超冷极性分子为探索多体物理的量子科学实验提供了一个令人兴奋的新平台。这个博士项目将使用最先进的设备，能够在微开尔文的温度下产生4000个基态红细胞分子的气体。该装置的工作原理是将铷（Rb）和铯（Cs）的超冷混合物中的原子结合在一起形成分子。这是完全相干地实现的，首先通过费什巴赫共振扫过磁场形成弱束缚分子，然后通过受激拉曼绝热通道将这些分子转移到深束缚状态。该项目将侧重于控制分子的内部和外部自由度。内部状态可以用微波完全控制，而光晶格，由驻波制成的陷阱，可以用来在空间上限制分子。一个关键的挑战是确定最大化分子在光学晶格中的旋转相干性的策略。在分子得到控制的情况下，该项目将研究利用分子丰富的内部结构作为合成维度，实现各种拓扑模型的量子模拟。

Ultracold polar molecules offer an exciting new platform for quantum science experiments exploring many-body physics. This PhD project will make use of a state-of-the-art apparatus capable of producing a gas of 4000 ground-state RbCs molecules at microkelvin temperatures. The apparatus works by binding together atoms from an ultracold mixture of Rubidium (Rb) and Caesium (Cs) to form the molecules. This is achieved fully coherently by first sweeping a magnetic field through a Feshbach resonance to form weakly-bound molecules, and then transferring these to deeply bound states by stimulated Raman adiabatic passage. The project will focus on controlling the internal and external degrees of freedom of the molecules. The internal state can be fully controlled with microwaves whilst optical lattices, traps made from a standing wave of light, can be used to confine the molecules spatially. A key challenge is to identify strategies to maximise the rotational coherence of the molecules in the optical lattice. With the molecules under control, the project will investigate using the rich internal structure of the molecule as a synthetic dimension to implement quantum simulation of various topological models.