Chemical Control of Spin and Carrier Dynamics in 2D Hybrid Metal Halide Double Perovskites

在化学系大分子、超分子和纳米化学（MSN）项目的支持下，加州大学圣克鲁兹分校的张晋教授和袁平教授正在使用先进的激光技术和计算方法相结合的方法来研究二维钙钛矿中电子自旋的行为。电子自旋是一种基本的量子力学性质，被用于许多新兴的量子技术。这些应用大多需要较长的自旋态寿命和精确的控制。然而，自旋寿命通常很短，只有百万分之一秒，而且很难操作。张和平教授以及他们的学生将创造出具有长自旋寿命的二维钙钛矿，并使用超快激光来控制它们的电子自旋。他们的发现可能会影响从纳米电子学到量子信息技术的技术。该项目还为未来的科学家提供先进仪器和计算方面的培训机会，并通过他们的“太阳，光谱学和圣克鲁斯”开放实验室活动，向当地高中学生和教师介绍他们的研究成果，以提高公众对科学的认识。研究小组将结合实验和理论努力，研究新型二维无铅金属卤化物双钙钛矿的自旋和载流子弛豫。本项目将系统研究结构、组成、表面、手性组分等基本因素对电子自旋寿命的影响，以及电子-电子、电子-声子散射等相关过程。该材料将在合理的结构和成分控制下合成，并结合时间分辨光致发光、透射电子显微镜、x射线衍射和光谱、拉曼和红外光谱以及超快泵浦探针方法对其进行仔细的表征。基于最先进的第一性原理开放量子动力学方法的计算研究将探索影响电子自旋寿命的散射过程，以指导和证实实验研究。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Macromolecular, Supramolecular, and Nanochemistry (MSN) program in the Division of Chemistry, Professors Jin Zhang and Yuan Ping of University of California-Santa Cruz are using a combination of advanced laser techniques and computational methods to investigate the behavior of electron spin in two-dimensional (2D) perovskites. Electron spin is a fundamental quantum mechanical property that is used in many emerging quantum-based technologies. Most of these applications require long spin state lifetimes and precise control. However, the spin lifetime is usually short, just a millionth of a millionth of a second, and it is challenging to manipulate. Professors Zhang and Ping and their students will create 2D perovskites with long spin lifetimes and use ultrafast lasers to control their electron spin. Their discoveries could impact technologies from nanoelectronics to quantum information technologies. The project also provides training opportunities for future scientists in advanced instrumentation and computation, and through their "The Sun, Spectroscopy, and Santa Cruz" open lab events, they will introduce their research findings to local high school students and teachers to enhance public awareness about science.The research team will combine experimental and theoretical efforts to study spin and carrier relaxation in novel 2D lead-free metal halide double perovskites. The project will systematically study the impact of fundamental factors, such as structure, composition, surface, and chiral component, on the electron spin lifetime, as well as associated processes such as electron-electron and electron-phonon scattering. The materials will be synthesized with rational structural and compositional control, and carefully characterized using a combination of time-resolved photoluminescence, transmission electron microscopy, X-ray diffraction and spectroscopy, Raman and infrared spectroscopy, as well ultrafast pump-probe methods. Computational studies based on a state-of-the-art first principles open quantum dynamics method will explore the scattering processes affecting electron spin lifetime to guide and corroborate experimental studies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.