Wang Investigates Dynamic Electron Spins in Correlated Magnets

This summer, Yishu Wang was awarded a $719,000 research grant from the United States Department of Energy (DOE) to study the dynamic and microscopic behaviors of magnets with quantum mechanical properties.

Magnetism originates from electrons in a material. When the electrons in a material all spin in the same direction, as they do in metals like iron, the material is magnetic, with poles that attract or repel other magnetic materials.

"Magnets that we are using today can be viewed as static orderings of electrons, analogous to the static pattern of brushstrokes in a painting," said Wang, a joint assistant professor in the Department of Materials Science and Engineering and the Department of Physics and Astronomy. "However, I and other researchers are investigating correlated magnets, which are defined by the vivid, coherent, and entangled dynamics of their electrons' spins. These magnets can't be understood from static patterns; they are more like movies than paintings."

The electrons in correlated magnets exhibit quantum mechanical interactions, leading to unconventional superconductivity, quantum entanglement, and other novel features. That gives correlated magnets strong potential in energy-efficient devices capable of high-speed computation, among other applications.

Adding Time Resolution to Neutron Scattering

Conventional neutron scattering—the typical method of investigating materials at the atomic scale—reveals limited snapshots of the electrons' spin-spin correlations but does not adequately capture the properties of novel magnets that lack a static ordering.

Over the next three years, Wang will use her DOE funding to develop a new capability of neutron scattering that will fully capture the spin dynamics in correlated magnets over time.

The preliminary data used in her grant proposal was analyzed by UT undergraduate computer science students.

"Working with undergraduate students from diverse academic backgrounds has been one of my greatest joys since becoming a faculty member at UT," Wang said. "Thanks to their work and this funding, we will be able to capture the dynamic behaviors of correlated magnetic systems with a refreshed perspective, gaining deeper insights into their underlying quantum mechanical interactions."

Throughout the grant, Wang will collaborate with colleagues at both UT and the Neutron Science Division at Oak Ridge National Laboratory (ORNL) who will help her synthesize correlated magnetic materials to investigate, develop and implement instrumentation to perform experiments, and interpret the experimental data.

The instruments and methods that Wang develops will remain available in ORNL's Spallation Neutron Source (SNS) for future studies.

"This research is particularly valuable to the quantum science community," Wang said, "but the development of neutron scattering with time resolution will benefit a range of scientific communities and help secure the SNS as the world's premier innovation center for neutron science."

Provided by University of Tennessee at Knoxville