A new $2 million grant from the National Science Foundation will help keep the University of Nebraska­—Lincoln at the forefront of advanced materials science. 

A team led by Evgeny Tsymbal, George Holmes Distinguished Professor of Physics, was one of 25 selected by the NSF through its Designing Materials to Revolutionize and Engineer our Future program. It is the first Nebraska-led project to be chosen for the NSF’s designing materials program, although several Nebraska physicists have participated in projects led by other institutions. 

“It is very prestigious for UNL to be selected as a lead university,” Tsymbal said. “It shows we are the leading edge of materials science and our research results are very highly valued. Our university has a rich history of advancing materials science, built through decades of collaborative research.” 

The federal program’s aim is getting advanced materials to market faster and cheaper than what is possible through traditional research methods. Selected research teams combine theory, data science and artificial intelligence with advanced synthetic and characterization techniques to discover novel materials and optimize their properties. 

Potential uses include semiconductors, quantum devices, wireless technology, biotechnology, efficient energy and resilient structural materials. In a world beset by climate, health and population challenges, these materials could translate into better and faster technology, less energy wastage, and shelters, transportation and tools capable of withstanding disaster. 

The Nebraska-led project involves experimental physicists from the University of Wisconsin, the University of Pittsburgh and Weizmann Institute in Israel. Tsymbal is a theoretical physicist who will use supercomputing capabilities at Nebraska’s Holland Computing Center to perform theoretical modelling that will be tested experimentally by his colleagues at the other institutions. 

Tsymbal’s efforts focus on a phenomenon known as moiré patterning to enhance the properties of oxide materials. 

Oxides, which are chemical compounds that include at least one oxygen atom bonded to another element, are powerful workhorses that can host almost every functional property known in solids. Their properties can be precisely adjusted at interfaces with other materials. 

“The practical significance of oxides lies in their potential to drive advances in energy-efficient information technologies, enable next-generation sensing and energy devices and serve as a foundation for emergent quantum technologies,” Tsymbal said. 

Moiré patterning refers to the new patterns and properties that emerge when two sheets of a material are placed on top of the other, with one at a different angle or twist from the other. The effect can be readily seen by layering two sheets of window screen and observing the different patterns that emerge as one sheet is turned so that the two lattices don’t precisely coincide. 

“We’ve learned you can do similar things using nanomaterials,” Tsymbal said. “Perovskite oxides, for example, have a crystalline structure. Crystals are made of atoms that repeat in a regular pattern, much like points on a lattice. If you create a very thin layer of the material and put another on top of it at a twist, new patterns and new features will emerge, which have not existed before in the material.” 

“This forms a superlattice that changes how electrons move and interact, giving rise to new quantum, electronic, and magnetic effects, since electrons are the basic carriers of both charge and magnetism.” 

Among promising oxides are ruthenites and manganites―ruthenium- and manganese-based compounds.  

“These complex oxide materials reveal interesting electronic and magnetic behavior when grown in very thin films,” Tsymbal said. “Through moiré patterning, they can induce vortex-like distortions in the atomic positions, forming a moiré lattice that modulates the material properties. They can also exhibit electronic localization―a state where electrons are trapped in certain regions instead of moving freely throughout the crystal. We want to resolve these features down to atomic scale and explore the emerging quantum properties.” 

Tsymbal’s project is one piece of the university’s broad focus on emergent quantum materials. The EQUATE (Emergent Quantum Materials and Technologies) collaboration, directed by Christian Binek, Paula and D.B. Varner Professor of Physics, is working to understand materials at the atomic level and is building upon research by this year’s Nobel Prize winners in physics and chemistry. A team led by Binek recently was awarded $1.8 million through the NSF’s EPSCoR program 

At UNL, the designing materials project will support research activities of a graduate student and a postdoctoral associate. Naafis Ahnaf Shahed, a graduate student of the Tsymbal group, has already been actively involved in computational studies of twisted oxide heterostructures that are directly relevant to the project. He is the first author of a recently published paper in Physical Review B on this topic. As part of the collaborative designing materials team, Naafis will continue exploring moiré-engineered oxide systems, focusing on their emergent electronic and magnetic properties and their potential for novel functionalities.

the Designing Materials to Revolutionize and Engineer our Future program is part of the Materials Genome Initiative, established in 2011 to increase the speed and decrease the cost of discovering and developing and deploying new advanced materials. NSF has awarded a total of $50 million to designing materials teams this year in what Tsymbal described as a highly competitive process.