The properties of a solid material depend not only on the molecules that are in it, but also on their exact structure. The arrangement of molecules is so important that advancing the design of quantum materials requires the study of matter down to the atomic level, says George Sawatzky, professor of physics & astronomy at the University of British Columbia and Founder of the Stewart Blusson Quantum Matter Institute.
“I’m very much interested in developing ideas for new experimental methods to study materials and their atomic properties, on a length scale which is of the size of an atom, because that’s basically what we’re getting down to,” explains Sawatzky.
For instance, take graphite, the material found in pencil leads. If you tear graphite apart into sheets that are just one atom thick, you get graphene: a material that conducts electricity even better than copper. These are the types of quantum materials that could be the foundation of future devices.
In parallel with new methods and measurements, Sawatzky develops a theoretical understanding of what he observes. That’s the key to smart design of the next generation of materials.
“Those experimental techniques are not simple,” adds Sawatzky. “They require a very deep level of quantum mechanical understanding to relate what you’re seeing to what the actual properties of the material really are.”
That atomic-level understanding led to an important breakthrough in designing materials with new properties.
“I’m particularly excited about the idea of being able to measure the motion of electrons in a solid, deep below its surface — in other words, at an interface between two different materials,” says Sawatzky.
“The idea was that if you took two materials and put them together, that the interface itself could have a very different property than either of the two materials, and that interface region could only be very, very thin. And that has turned out to be correct.”
That opens up many opportunities for materials to have novel properties by assembling existing materials in new architectures. Nanostructured materials have potential for use as high temperature superconductors or other materials for advanced electronic devices.
The properties that can be achieved by designing new structures and combinations of materials may be surprising, and the results may even seem like alchemy without the understanding to back them up. By working on both sides of this research in tandem, researchers can accelerate the development of the next generation of quantum materials.
