Molecules for Quantum simulation

量子模拟分子

• 批准号: MR/X033430/1
• 负责人: Hannah Williams
• 金额: $ 175.99万
• 依托单位: Durham University
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FX033430%2F1
• 关键词: Molecules; Quantum; simulation

In order to fully understand the universe at a quantum level, we can't rely on classical computers. This is because matter is too complicated, for example, materials consist of large numbers of particles all interacting with one another and the computer memory required to calculate the evolution of such a system grows exponentially with the number of particles. A better route is to recreate the system using quantum particles. In this project we will be using ultracold molecules as the basis for a quantum simulator. There currently exist quantum simulators based on trapped ions, Rydberg atoms and superconducting circuits. Each platform has its own strengths and weaknesses. Molecules, much like Rydberg atoms, provide an easily scalable route to large numbers of particles. However, molecules have very long-lived states and a rich internal structure. This structure offers different energy scales which can be explored, over 4 orders of magnitude, and the possibility of adding an extra synthetic dimension. In addition, ultracold, controlled molecules can be used for tests of fundamental physics, and studies of quantum chemistry. The techniques demonstrated in this project will contribute to these fields as well.Over the last decade, techniques have been developed to create very cold clouds of molecules, and recently the first molecules were loaded into individual optical traps - known as tweezers. I am going to build a new experiment, based on these methods, to create arrays of molecules in tweezers. I am going to demonstrate control over the motion of the molecules in tweezers for the first time, such that they are pinned to the minimum of each trap. I will also control the internal quantum state of the molecule - by adding and removing energy from the rotation of the molecule. By doing this I will create what is known as a superposition of rotational states. A superposition is a quantum mechanical phenomenon where a particle can exist in two states at once. In such a superposition, molecules will interact strongly with one another providing the coupling required to simulate a system. I will study this interaction, called the dipole-dipole interaction, and measure its dependency on external parameters such as the geometry of the trap arrays. To truly benefit from the advantages offered by molecules, we want to load them into an optical lattice which has smaller intersite separation (down to half the wavelength of the trapping light i.e. ~400 nm) and can allow for tunnelling between sites as well as the dipole-dipole interaction. This leads to exotic phases which cannot be accessed by other platforms. This will be the next stage of the project, leading to a versatile, programmable quantum simulator.

为了在量子水平上完全理解宇宙，我们不能依赖经典计算机。这是因为物质太复杂了，例如，材料由大量相互作用的粒子组成，计算这样一个系统的演化所需的计算机内存随着粒子数量的增加而指数增长。一种更好的方法是使用量子粒子重建系统。在这个项目中，我们将使用超冷分子作为量子模拟器的基础。目前存在基于俘获离子、里德堡原子和超导电路的量子模拟器。每个平台都有自己的优势和劣势。分子，很像里德堡原子，提供了一条容易扩展的路线，可以到达大量的粒子。然而，分子具有非常长的寿命和丰富的内部结构。这种结构提供了可以探索的不同能量尺度，超过4个数量级，并有可能增加一个额外的合成维度。此外，超冷、受控分子可用于基础物理测试和量子化学研究。这个项目中展示的技术也将对这些领域做出贡献。在过去的十年里，已经开发出了创造非常冷的分子云的技术，最近第一批分子被加载到单独的光学陷阱中--也就是众所周知的镊子。我将在这些方法的基础上建立一个新的实验，在镊子中创建分子阵列。我将第一次演示对镊子中分子运动的控制，使它们被固定在每个陷阱的最小限度。我还将控制分子的内部量子态--通过增加和移除分子旋转的能量。通过这样做，我将创建所谓的旋转态的叠加。叠加是一种量子力学现象，其中一个粒子可以同时以两种状态存在。在这样的叠加中，分子将彼此强烈地相互作用，提供模拟系统所需的耦合。我将研究这种相互作用，称为偶极-偶极相互作用，并测量它对外部参数的依赖，例如陷阱阵列的几何形状。为了真正从分子提供的优势中受益，我们希望将它们加载到一个具有较小的点间间隔(降至捕获光波长的一半，即~400 nm)的光学晶格中，并允许位置之间的隧穿以及偶极-偶极相互作用。这导致了其他平台无法访问的奇异阶段。这将是该项目的下一阶段，导致一个多功能的，可编程的量子模拟器。