Working with theorists in the Pritzker School of Molecular Engineering (PME) at the University of Chicago, researchers in the U.S. Department of Energy’s (DOE) Argonne National Laboratory have achieved a scientific control that is a first of its kind. They demonstrated a novel approach that allows real-time control of the interactions between microwave photons and magnons, potentially leading to advances in electronic devices and quantum signal processing.
Microwave photons are elementary particles forming the electromagnetic waves that we use for wireless communications. On the other hand, magnons are the elementary particles forming what scientists call "spin waves" – wave-like disturbances in an ordered array of microscopic aligned spins that can occur in certain magnetic materials.
Microwave photon-magnon interaction has emerged in recent years as a promising platform for both classical and quantum information processing. Yet, this interaction had proved impossible to manipulate in real-time, until now.
“Before our discovery, controlling the photon-magnon interaction was like shooting an arrow into the air,” said Xufeng Zhang, an assistant scientist in the Center for Nanoscale Materials, a DOE User Facility at Argonne, and the corresponding author of this work. “One has no control at all over that arrow once in flight.”
The team’s discovery has changed that. “Now, it is more like flying a drone, where we can guide and control its flight electronically,” said Zhang.
By smart engineering, the team employs an electrical signal to periodically alter the magnon vibrational frequency and thereby induce effective magnon-photon interaction. The result is a first-ever microwave-magnonic device with on-demand tunability.