The quantum computing era demands novel materials and approaches to overcome the challenges of quantum information storage and scaling up quantum-interconnected circuits. Magnons may provide a pathway toward overcoming both obstacles. These quasiparticles represent collective waves of synchronized electron spins that travel through magnetic materials and can carry quantum information at both nano- and macroscopic scales. But until now, there has been a major roadblock on the way to their implementation – an extremely short lifetime of a few hundred nanoseconds.
In a recent research breakthrough, Associate Professor Dmytro Bozhko, Ph.D., and former physics undergraduate student Kaitlin McAllister, along with fellow researchers, have extended magnon lifetimes to 18 microseconds – over a hundred times compared to the previously reported values – an outcome previously thought possible only in theory.
In “Ultralong-living magnons in the quantum limit,” Bozhko, McAllister, and their co-authors detail how magnon lifetimes can be extended under the right circumstances and how this leads to much more potential for their ability to improve quantum computing.
“Our research shows that magnons can persist for far longer when they are created with sufficiently short wavelengths in exceptionally pure material, and cooled to extremely low temperatures,” explained Bozhko. “The most fascinating result is that there is no limit in how long magnons can live, we just need to create more pure materials.”
“Our work really sets the momentum for further breakthroughs,” continued Bozhko. “Ongoing efforts are focused on designing experiments to create magnonic quantum gates and interfaces. We expect that our work will spark a strong material research effort to make more pure magnetic materials for the next generation of magnonic quantum technologies. With these results, we are extremely close to creating useful magnetic quantum computing circuits.”
The success of the project was brought together by complementary expertise from institutions not only from the U.S., but also from Austria, Germany and Ukraine.
“The work required ultra-pure magnetic materials, advanced cryogenic measurements, precision spectroscopy, meticulous assembly of the experimental setup and systematic measurements, followed by comprehensive data analysis and theoretical interpretation,” Bozhko shared. “In this respect, a contribution from a talented undergraduate student, Kaitlin McAllister, was especially important from the UCCS side. While working in the Microwave Magnonics Group and visiting the lab of collaborators at the University of Vienna, she performed experimental studies at cryogenic temperatures as well as evaluated the data.”
This research, as well as Bozhko’s broader research program in quantum magnonics, is supported by the U.S. National Science Foundation (NSF) through NSF CAREER Award, “Fundamental Phenomena in Magnon Condensates” (Award No. DMR-2338060).