Like fans that blow in sync, certain magnetic materials can exhibit interesting energetic properties.
In order to find new ways to transmit and process information, scientists have begun to explore the behavior of electronic and magnetic spins, specifically their resonant excitations, as information carriers. In some cases, researchers have identified new phenomena that could help eventually inform the creation of new devices for spintronic and quantum applications.
In a new study led by the U.S. Department of Energy’s (DOE) Argonne National Laboratory, researchers have uncovered a novel way in which the excitations of magnetic spins in two different thin films can be strongly coupled to each other through their common interface. This dynamic coupling represents one kind of hybrid system that is getting increasing amounts of attention from scientists interested in quantum information systems.
“One way to think about it is as though you have two pairs of masses attached to springs,” said Argonne postdoctoral researcher and first author Yi Li. “We know that each mass connected to a spring will oscillate periodically when it’s hit from the outside. But if we connect the two masses with a third spring, then the oscillation of one mass will also trigger the oscillation of the other mass, which can be used to exchange information between the springs. The role of the third spring here is played by the interfacial exchange coupling between the two magnetic layers.”
With some smart engineering, researchers can set the free oscillation frequency of the two layers of magnetic spins — the “masses” — to be identical, where they are the most favorable to couple. In addition, they show that the two systems can be “strongly” coupled, a state which is important to maintain coherence and may inspire applications in quantum information.
Read more at Argonne National Laboratory.
Image: Researchers at Argonne have found a new platform for coherent information transduction with magnons in an exchange-coupled magnetic thin film bilayer. The results show new insights in both fundamental physics and device potentials for spintronics and quantum applications. (Image by Argonne National Laboratory.)