RII Track-4:NSF: Direct and Complete Characterization of Electronic Properties of Materials Under Pressure

金刚石砧细胞是在极端压力（数千到数百万个大气压）下探测材料的强大工具，但是从DAC实验中提取的电子信息通常受到压力装置本身的材料和几何约束的限制——样品被毫米级的金刚石和英寸级的钢包围。固态高谐波产生光谱（sHHG）是一种研究材料电子和结构特性的新兴技术，它利用超快激光激发电子并利用光谱学探测电子，从而为在极端压力下收集材料的详细电子信息提供了全光途径。这个NSF EPSCoR RII Track-4研究项目结合了内华达大学拉斯维加斯分校（UNLV）的高压专业知识和加州大学伯克利分校（UCB）的世界领先的超快光谱能力，提供了一种在极端压力下直接测量材料电子能带结构的方法。由此产生的新方法将为研究人员提供一种直接测量高压下材料特性的方法，这些特性目前是由伴随的计算推断出来的，该项目还将使UNLV的学生在世界领先的机构中接触到尖端技术。这个NSF EPSCoR研究基础设施改善轨道4研究员（RII轨道4）项目提供奖学金在UNLV研究助理教授在他们的学术生涯的关键时刻，并支持研究生参加他们的第一个实验。这个项目的重点是固体高谐波产生光谱的应用材料在极高压的金刚石砧细胞。这些结果可以用来构建它们的电子能带结构——这些信息是目前可用的实验方法无法获得的。这种发展将填补长期以来高压研究的空白，PI和主机将准备将他们的新技术应用于一系列问题，包括跟踪压力诱导的电子相变和高压下的原位化学反应。项目负责人和学生将有机会在主办机构使用独特的、世界领先的设备，并将帮助进一步开发这些设备，以适应高压实验。该奖学金将促进UCB和UNLV之间的紧密联系，该机构是少数族裔服务机构，第三类亚裔美国人和美洲原住民，太平洋岛民服务机构，以及第五类西班牙裔服务机构。这将证明对初级PI的职业生涯和UNLV的研究基础设施具有变革性，因为新的专业知识将在其校园中出现。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。

The diamond anvil cell is a powerful tool for probing materials at extreme pressures (thousands to millions of atmospheres), but electronic information that can be extracted from DAC experiments is often limited by the material and geometric constraints of the pressure device itself — the sample is surrounded by millimeters of diamond and inches of steel. Solid-state high harmonic generation spectroscopy (sHHG) is an emerging technique for studying electronic and structural properties of materials which uses ultrafast lasers to excite electrons and optical spectroscopy to probe them, thus providing an all-optical avenue to gleaning detailed electronic information on materials at extreme pressure. This NSF EPSCoR RII Track-4 research project combines high-pressure expertise from the University of Nevada, Las Vegas (UNLV) with world-leading ultrafast spectroscopy capabilities at the University of California, Berkeley (UCB) to deliver a method to measure electronic band structures of materials at extreme pressures directly. The resulting new methodology will provide researchers with a means to directly measure properties materials at high pressure which are currently inferred from accompanying computation, and the project will also expose UNLV students to cutting-edge techniques at a world-leading institution.This NSF EPSCoR Research Infrastructure Improvement Track-4 Research Fellows (RII Track-4) project provides a fellowship to a Research Assistant Professor at UNLV at a critical juncture of their academic career, and support for a graduate student to participate in first-of-their-kind experiments. The focus of this project is the application of solid-state high harmonic generation spectroscopy to materials at extreme high pressures in a diamond anvil cell. The results can be used to construct their electronic band structures — information which is not possible to garner using currently available experimental methodologies. A development of this kind will thus fill a longstanding gap in high-pressure research, and the PI and the host will be poised to apply their new technique to a range of problems, which involve tracking pressure-induced electronic phase transitions and chemical reactions in situ at high pressures. The PI and students will have access to unique and world-leading facilities at the host institution and will aid in further developing those facilities for compatibility with high-pressure experiments. The fellowship will foster a strong tie between UCB and UNLV, a Minority-Serving Institution, Title III Asian American and Native American, Pacific Islander-Serving Institution, and a Title V Hispanic-Serving Institution. This will prove transformative to the career of the junior PI, and to the research infrastructure at UNLV owing to the new expertise which will be made present on its campus.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.