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

钻石顶压室是在极端压力(数千到数百万个大气压)下探测材料的强大工具，但从DAC实验中提取的电子信息往往受到压力装置本身的材料和几何约束的限制--样品周围环绕着毫米厚的钻石和英寸厚的钢。固态高次谐波产生光谱(SHHG)是一种新兴的研究材料电子和结构性质的技术，它利用超快激光激发电子，用光学光谱探测电子，从而提供了一种在极压下收集材料详细电子信息的全光学途径。NSF EPSCoR RII Track-4研究项目将内华达大学拉斯维加斯分校(UNLV)的高压专业知识与加州大学伯克利分校(UCB)世界领先的超快光谱能力相结合，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在高压下直接测量材料性能的手段，这些材料目前是从伴随的计算中推断出来的，该项目还将使UNLV的学生接触到世界领先机构的尖端技术。NSF EPSCoR研究基础设施改进Track-4研究人员(RII Track-4)项目为UNLV的研究助理教授在其学术生涯的关键时刻提供奖学金，并支持研究生参与首次此类实验。该项目的重点是将固态高次谐波产生光谱技术应用于金刚石顶压室中处于极高压力的材料。这些结果可以用来构建它们的电子能带结构--这是目前可用的实验方法无法获得的信息。因此，这种发展将填补高压研究中的一个长期空白，PI和东道主将准备将他们的新技术应用于一系列问题，其中包括在高压下原位跟踪压力诱导的电子相变和化学反应。国际和平研究所和学生将有机会在主办机构使用独特的世界领先的设施，并将帮助进一步开发这些设施，以与高压实验兼容。该奖学金将促进UCB与UNLV之间的牢固联系，UNLV是一个少数族裔服务机构，第三章亚裔美国人和土著美国人，太平洋岛民服务机构，以及第五章拉美裔服务机构。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，因为将在其校园内提供新的专业知识。这一奖项反映了NSF的法定使命，并通过使用基金会的智力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.