Harold Hwang Wins 2024 McGroddy Prize for Material Discovery

The wonders of modern technology – computers that fit in your hand, internet-connected refrigerators and self-driving cars – are only possible thanks to the magic of materials like silicon. Likewise, tomorrow’s science fiction gadgets will emerge from the exotic new materials scientists discover today.

Harold Hwang, a physicist at the Department of Energy’s SLAC National Accelerator Laboratory and Stanford University, has brought this future closer by joining carefully crafted materials and seeing what happens where they touch. His experiments have uncovered a large number of compounds with surprising properties, including an entirely new class of superconductors. Now, the American Physical Society has awarded Hwang the 2024 James C. McGroddy Prize for New Materials to celebrate his groundbreaking research.

The award recognizes Hwang for “outstanding achievements in the science and application of new materials,” work that spans his decades-long career.

“It’s a great honor,” Hwang said, quickly sharing the honor with his colleagues at the Stanford Institute for Material and Energy Sciences. “This really represents a lot of students, postdocs and employees.”

Hwang and his group make super-thin sheets of different materials, just one molecule thick, and then stack them in different combinations to find out how they behave. “We have a finite number of ingredients in the periodic table,” says Hwang, “and yet it’s so remarkable that you put two things together and you can get everything under the sun.”

Hwang and his laboratory focus, among other things, on superconductors, which conduct electricity without any resistance or wasted energy.

If all electronics were superconductors, our entire electrical grid would be much more efficient and new technologies would become possible. But to turn a metal into a superconductor, researchers usually need to cool it to about the temperature of space, which is only possible in specialized laboratory environments.

In 1986, a family of copper-based materials were discovered that were later found to be superconducting at relatively milder temperatures, about 200 degrees below zero Fahrenheit, which can be achieved by immersing them in liquid nitrogen. No one understands exactly what makes these “unconventional” superconductors work, but their discovery inspired hopes that lossless electronics could one day become much more integrated into our daily lives.

In 2019, Hwang and his team of chemical explorers discovered a superconducting mixture of nickel and oxygen, reviving this hope. Because nickel and copper are so similar — they are next to each other on the periodic table of elements — scientists have long thought that nickel-based superconductors could operate at similarly high temperatures. However, synthesizing it took decades of trial and error. “There were very different approaches that people took. This is just the first one that was successful,” says Hwang. “We were lucky.”

Figuring out how unconventional superconductors work could be much easier now that scientists have another type to study. With such insight, researchers aim to create superconductors that require no coolant at all, which would make the technology much more accessible for everyday applications.

In addition to superconductors, Hwang and his group’s material mashups also include a method of producing an oxide film on a substrate, then removing the substrate and transferring the film to any desired material. They also used their expertise in oxide manipulation to design new catalysts that could split water into oxygen and hydrogen, which could help develop new clean ways to store energy.

There’s a common theme: Hwang enjoys doing basic science that can lead to real-world impact. “What I like is that relatively few people with relatively limited resources have all the ingredients to pursue an idea, try to make that idea a reality and bring it back into our daily lives.”