CAREER: QUANTUM MATERIALS IN SQUARE-NET BASED COMPOUNDS

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). NON-TECHNICAL SUMMARY

So-called "Quantum-materials" are materials that do not follow the laws of classical physics. Examples are superconductors, complex magnets, or topological materials. Topological materials are a class of quantum matter that show promise to enable future technologies such as new devices for data storage or quantum computing.

Not much is yet understood, however, about the materials chemistry of topological matter. With this CAREER award, Professor Leslie Schoop at Princeton University aims to understand how the discipline of solid-state chemistry can impact the understanding of topological matter. Towards this goal, the team will focus on a particular class of crystalline compounds: those in which atoms arrange in a square-net fashion.

In these materials, electronic properties can be understood on the basis of the chemical bonds in the square lattice. Understanding the nature of the chemical bonds then allows the intentional modification of these bonds and how this effects physical properties, such as electronic and magnetic properties. Ultimately, Prof.

Schoop’s team will create a recipe for discovering quantum properties in materials with square nets. This proposal also includes outreach to community colleges by providing support for students from New Jersey-based community colleges to spend a summer in the Schoop lab to learn more about quantum materials synthesis. The PI will visit these community colleges to give lectures targeted to a general audience to provide basic insights to the complex and exciting field of quantum materials.

TECHNICAL SUMMARY

With this CAREER award, Professor Leslie Schoop at Princeton University aims to establish predictive power for the development of new quantum materials based on a class of compounds with a common structural motif - a square net. In this class of materials, a topological electronic structure can be linked to the type of chemical bonding within the square net.

This delocalized bonding has been classified as hypervalent and is in direct competition to a charge density wave-type lattice distortion. The aim here is to understand the effect of such distortions on the topological band structure. Charge density waves in topological materials have recently gained attention because they provide a pathway for the creation of multiple new correlated topological phases that still have yet to be discovered.

This project addresses the current challenges from a chemical angle. The second aim is to use the structural distortions as a tool to create materials with complex magnetism. Magnetism has the potential to add electron-electron correlation to a topological material.

Such correlated topological materials are believed to result in the discovery of yet unknown physics, which could lead to new quantum devices. The goal will be reached by synthesizing and structurally characterizing multiple square-net materials, as well as by varying their composition. The structural data will be used to derive chemical rules for structural distortions.

Finally, the magnetic and electronic properties of the synthesized compounds will be investigated. The Broader Impacts consists of student education; a commitment to diversity; service to the community; and the potential for advancing technology. The PI will provide opportunities to New Jersey community college students to work in her lab while reaching out to these campuses with public lectures to help underrepresented minority students understand different possible STEM Career paths.

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.