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

University Of Nevada Las Vegas, Las Vegas NV

Investigators

Abstract

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.