Theory of interacting quantum many-body systems of atoms and photons

冷原子系综是构建光与物质之间量子界面的关键平台，是从原子钟到量子信息处理等新兴量子技术的基础科学。近年来，纳米光子学的一个成功案例是人工制造由典型亚波长大小的散射体的纳米结构薄膜形成的超表面，用于光的操纵、检测和控制。利用冷原子的类似超表面可以通过将原子放置在二维平面阵列中来构建，例如在光学晶格中。单层亚波长间隔原子形成量子纳米光子表面，其中散射光介导强协同相互作用。紧密捕获的原子形成了一种特征良好的介质，其中每个原子具有完全相同的共振频率和线宽，所有与原子相互作用的光都被发射回来而不被吸收，甚至大型阵列原则上也可以在单光子量子极限下工作。该项目旨在开发理论工具，用于分析原子和光的量子多体系统，并对其进行数值求解。然后可以利用合作相互作用来开发光的量子光学操作的应用。监督是通过导师和学生之间的会议和讨论进行的，大约每1-2周进行一次，或者在出现特殊需求时更频繁。

Cold atomic ensembles constitute a key platform for constructing quantum interfaces between light and matter that are the underpinning science for emerging quantum technologies from atomic clocks to quantum information processing. One of the success stories of nanophotonics in recent years has been artificially fabricated metasurfaces formed by thin nanostructured films of typically subwavelength-sized scatterers for the manipulation, detection, and control of light. Analogies of such metasurfaces utilizing cold atoms can be constructed by placing atoms in two-dimensional planar arrays, e.g., in optical lattices. A single layer of subwavelength-spaced atoms forms a quantum nanophotonic surface where scattered light mediates strong cooperative interactions. Tightly trapped atoms form a well-characterized medium where every atom has precisely the same resonance frequency and linewidth, all the light interacting with atoms is emitted back with no absorption, and even large arrays can in principle operate in a single-photon quantum limit.The project is to develop theoretical tools for analysing such quantum many-body systems for atoms and light, and to solve them numerically. Cooperative interactions can then be harnessed to develop applications for quantum-optical manipulation of light. The supervision is conducted by meetings and discussions between the supervisor and student approximately every 1-2 weeks, or more frequently when special needs for those arise.