Imaging Ultrafast and Ultrasmall: Understanding and Manipulating Phase Transitions in Correlated Oxides Using Coherent X-Ray Diffraction

University Of California-Davis, Davis CA

Investigators

Abstract

NON-TECHNICAL DESCRIPTION: Modern-day semiconductor devices have led to important advances in diverse areas including information technology, energy, health, and education. To overcome the current plateau in performance of the existing microelectronics and enable energy-efficient high-speed operation, complex oxides have been identified as a possible alternative to semiconductors. This project explores the novel approach of utilizing optical lasers to manipulate magnetic and electronic properties of complex nickel oxides at ultrafast timescales. Research activities involve synthesis and advanced characterization of complex oxides at nanometer lengthscales and femtosecond timescales. The fundamental understanding of nanoscale and ultrafast phenomenon is expected to significantly impact the development of future generations of computing devices. Education activities includes introducing women and minority undergraduate students to opportunities at U.S. National Laboratories and collaborating with University of California Davis Mathematics Engineering Science Achievement (MESA) Schools Program to engage high school students in science, technology, engineering, and mathematics. This project will provide graduate and undergraduate students training in interdisciplinary fields at the intersection of materials science, physics, and electrical engineering. Graduates are likely to find future employment in the information technology sector. TECHNICAL DETAILS: The goal of this research project is to elucidate fundamental limits and mechanisms to tailor material properties at ultrasmall lengthscales and ultrafast timescales in correlated oxides including rare-earth nickelates such as neodymium nickelate and samarium nickelate. The project focuses on optically induced metal-insulator phase transitions in rare earth nickelate thin films by utilizing synchrotron and free electron laser based coherent X-ray techniques. Specific objectives include: (i) deciphering fundamental lengthscales and timescales associated with ultrafast behavior, (ii) understanding the influence of nanoscale morphology in optically induced phase transitions, and (iii) investigating the coupling of electronic, magnetic and structural degrees of freedom at femtosecond timescales. The scientific knowledge at the ultimate limits of the ultrafast/ultrasmall frontier in materials behavior discovered in this project will enable development of future generations of computing devices based on light-matter interactions. Education activities include the training of undergraduate and graduate students in state-of-the art deposition and characterization tools, including synchrotron radiation and free electron laser-based characterization techniques at U.S. National Laboratories. 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.