CAREER: Van der Waals heterostructures of magnetic oxide membranes

University Of California-Davis, Davis CA

Investigators

Abstract

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Non-Technical Abstract: Metal oxides exhibit an incredibly broad range of physical properties including magnetism, metal/insulator transitions, ferroelectricity, and superconductivity. Oxide heterostructures, consisting of multi-layer thin films synthesized by thin-film epitaxy, often accommodate new exotic phenomena by interfacing dissimilar materials. The proposed research aims to design a new type of oxide heterostructures by mechanically stacking oxide membranes of freestanding geometry. The stacked oxide membranes offer a number of interesting combinations in designing interfacial magnetic properties which can be useful for future information technologies. This CAREER project also aims to integrate the research with education and outreach activities involving K-12, undergraduate, and graduate students. The combined research-education activity targets training the next generation STEM workforce, particularly in the field of quantum materials and condensed matter physics. Technical Abstract: Mechanically assembled van der Waals (vdW) heterostructures of oxide membranes hold an enormous potential in designing new complex oxide materials not limited by epitaxial conditions. Understanding fundamental properties of such oxide vdW interfaces is crucial in designing novel quantum ground states. The CAREER project focuses on vdW heterostructures of magnetic oxide membranes. The research aims to understand unconventional magnetic ground states formed at the oxide vdW interface, where exchange interaction, spin-orbit coupling, and Moiré lattices are carefully designed to manipulate exotic topological electromagnetic structures. The main experimental activities involve materials synthesis, heterostructure assembly, electronic and magnetic characterizations, and collaborative efforts using optical spectroscopy and local magnetometry. The combination of new materials synthesis and multiple characterization approaches, guided by theoretical calculations, provides profound insight to understand the emergent magnetic structures at oxide vdW interfaces. 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.