基于囚禁离子探针的金属表面噪声实验研究

Since electric-field noise and energy dissipation near surfaces and interfaces present challenges in many fields of science and technology, people have been looking for an effective way to studying the origin and physical mechanism of the noise. The ultracold ions can be a nanoscale prober for studying this noise. The ultracold ions are interfered significantly by the electrode surface noise with the decrease of the trap electrode size, and the quantum states of the trapped ions could be precisely manipulated and measured by lasers. This provides a brand-new way to study the surface electric field noise in a quantum fashion. The applicant's team has cooled the trapped ions down to the ground states, and achieved the manipulation and readout of the quantum states. Based on this fact, the project aims to experimentally investigate the electric field noise on the carried metal surface by the trapped-ion platform. The main work includes: Combining with the processing and measurement tools of the surface science, we study the physical mechanism of the electric field noise of the metal surfaces; By selecting different surface adsorptions, we investigate the thermal excitation processes of the surface states. This project works by combining the theoretical study with the experimental implementation, not only with the new physical system to scrutinize the surface noise, but also with in-depth study of the origin and the physical mechanisms of the surface noise by analyzing the experimental results.

目前许多科学技术领域都面临着电场噪声以及表面和界面上能量耗散的问题，人们一直在寻求一种有效的途径来研究这种噪声的来源和物理机制。超冷离子可以作为一个纳米尺寸的探针用于研究这种噪声。这是由于超冷离子随着阱电极结构的减小受到电极表面噪声的作用显著增加；而超冷离子的量子态可以通过激光精确的操纵和测量，这为在量子层次上研究表面电场噪声提供了一种崭新的途径。申请人的团队已经能够将离子冷却到振动基态，并已实现了量子态的操纵和读出。本项目基于申请人团队的超冷离子研究平台，开展金属表面电场噪声的实验研究。主要研究工作包括：结合表面科学中的现场处理和测量工具，研究纯金属表面的电场噪声的物理机制；通过选择不同的表面吸附物，研究表面态的热激发过程。本项目着眼于理论结合实验进行，不仅采用新的物理体系对表面噪声开展实验研究，同时从理论上对实验结果进行分析，深入探究表面噪声的来源和物理机制。

目前许多科学技术领域都面临着电场噪声以及表面和界面上能量耗散的问题，人们一直在寻求一种有效的途径来研究这种噪声的来源和物理机制。囚禁在离子阱芯片中的超冷离子随着阱电极结构的减小受到电极表面噪声的作用显著增加；而且超冷离子的量子态可以通过激光精确的操纵和测量，这为在量子层次上研究表面电场噪声提供了一种崭新的途径。本项目基于超冷离子作为一个纳米尺寸的探针用于研究这种噪声。申请人通过本项目的探索，将囚禁的离子冷却到多普勒极限，离子温度降低至0.6mK，测量了不同离子数以及离子阱芯片不同位置的加热速率，研究了单个离子在囚禁势场由单势阱变化到双势阱过程中的非线性运动，以及操控了离子库伦晶体结构相变过程，研究了离子晶体温度对结构相变过程的影响。本项目发表论文7篇，获得发明专利授权1项，其中Physics Review Letters 1篇，Phyics Review A 3篇。本项目的开展帮助我们掌握了金属表面噪声的探测和分析方法，为下一步开展金属表面吸附动力学的研究打下了良好基础。