Rutgers professor has been given award from Air Force for his research

Dr. Jedediah Pixley, an assistant professor in the Department of Physics and Astronomy, has recently been awarded the Young Investigators Research Program (YIP) award by the Air Force Office of Scientific Research (AFOSR) for his research in atomic and molecular physics.

The AFOSR awarded a total of $17.8 million in grants this year after selecting 40 of the 220 reviewed proposals, according to the Wright-Patterson Air Force Base website. Pixley was one of these 40 scientists and engineers who won the award, and he is eligible for a three-year grant totaling $450,000.

Pixley was at a cousin’s wedding when he learned that he was the recipient of the grant, he said. 

“It was a complete surprise,” Pixley said. “This was my third time applying, and I didn’t know if I would get it.”

The chair of the Department of Physics and Astronomy, Robert A. Bartynski, said Pixley is the first faculty member in the department to receive this particular award.

Pixley’s submission, titled "Emulating Twistronics and Beyond with Ultra-Cold Atoms," proposes to build off of an exciting discovery in physics just last year. 

“In March of 2018, there was a very exciting experiment announced — that you can take two sheets of graphene and twist them, one relative to another, and that’s what twistronics are, twisting 2D materials,” Pixley said. “It was discovered that these become superconductors, even though you start with weakly interacting semiconductors.”

Pixley described how twisting sheets of materials can change the superconductivity of a material. 

“Each sheet has its own crystal lattice, its own shape, and when you twist them, you get these things called Moiré patterns, where these two shapes interfere, and it almost looks like you have a new lattice with a much bigger length scale,” he said. “So now, the electrons want to tunnel on this new length scale, they want to hop between these new Moiré sites, but they have to hop much further and their velocity slows down.”

The decrease in velocity means that the electrons become strongly interactive, Pixley said. 

“So what you’re doing is you’re not making the interactions larger, you’re just making the kinetic energy smaller, so the interactions dominate,” he said. “And that’s how you make superconductivity — or what we think is how you make superconductivity.”

Pixley also said he plans to expand on this recent discovery. 

“My proposal is about how you can realize the same phenomenon, but by studying a gas of ultra-cold atoms that can be trapped with lasers and cooled down to nano-Kelvin temperatures,” he said. 

He plans to study the theoretical implications and determine how this effect can be used in other settings.

Pixley offered an explanation as to why the Air Force may be interested in this technology. “I think the interest in atomic physics – using atomic physics to emulate solid-state systems – has been a big field of research that the Air Force has been interested in,” he said. “They’ve been trying to understand these high-temperature superconductors by emulating material that we have in the lab using a gas of atoms.”

Further research into twistronics may help uncover the unknown details of superconductivity, Pixley said. 

“High-temperature semiconductors become superconductors at temperatures that are not too low, and we don’t really understand why,” Pixley said. “We have some theories but there’s no consensus on why they superconduct, so we’re trying to find other systems that are similar to these high-temperature superconductors.”

Pixley is looking forward to the next three years to continue his research into twistronics and make full use of the grant, he said. 

“It’ll enable us to really explore lots of different settings where you can use this effect of twistronics in settings that you could never have thought of before,” Pixley said. “If you can solve the much simpler models, you can explain the more complicated settings, so now that we understand this effect, we can generalize it.”

The grant will help fund the instrumentation and personnel needed for Pixley’s research, Bartynski said. 

“Support from external grants is an essential component to any successful research program,” he said.

Pixley credited help from his colleagues in his department to his success as well. 

“It’s such a great place to be,” Pixley said, referring to Rutgers. “There are so many people to talk with and work with, and it’s a great department.”

Bartynski added to this reflection, pointing to the success of many faculty members in the department. 

“We have had many young faculty members receive early career awards from the National Science Foundation and the Department of Energy,” Bartynski said. “Faculty members often write several grant proposals per year. The success rate is far from 100%, true for any program, but our success rate is well above the averages posted by the funding agencies.”

Pixley ended with some advice to undergraduate students. 

“Don’t give up. Just keep going. I got two no's to the yes, so I had to try three times,” Pixley said, laughing, referring to his two unsuccessful submissions to the AFOSR. “Don’t give up on your first try.”