New Technology opens the door to the next generation of information processing.

The new technology opens the door to improved information transfer in quantum and classical regimes.

Many of us pass through gates daily – points of entry and departure to spaces like parks, gardens, or subways. Gates can also be found in electronic devices. These gates control information flow by using an electrical signal. These gates are much faster than a garden gate and require opening and closing quickly.

Researchers at the U.S. Department of Energy (DOE), Argonne National Laboratory, and the University of Chicago’s Pritzker School of Molecular Engineering devised a unique way to achieve effective gate operation using information processing electromagnetics. This breakthrough allows for real-time control over information transfer between magnons and microwave photons. It could lead to a new generation of classical electronic and quantum signal devices that can be used for signal switching, low-power computing, and quantum network.

The elementary particles that makeup microwave photons form the electromagnetic waves used in wireless communications, such as wireless communications. Magnons are particle-like representations of a “spin wave,” an array of locks in an ordered array macroscopically aligned in magnetic materials.

“Many research teams are combining different types of data carriers for information processing,” stated Xufeng Zhang, assistant scientist at the Center for Nanoscale Materials, a DOE Office of Science Facility at Argonne. “Using information carriers of different types would not allow for practical applications. Such hybrid systems would be able to enable them to do things that are impossible with one type.”

Zhang stated that signal processing that couples microwaves and spin waves are high-wire. “The signal must be coherent, despite any energy dissipations or other effects that could throw the system into chaos,” Zhang said.

In hybrid magnonic systems, coherent gate operation (control of on, off, and duration) has long been a desired goal. This can be achieved by rapidly tuning the energy levels between photons and magnons. This tuning is possible only if the device’s geometric configuration changes. This takes, on average, 100 nanoseconds (one hundred billionths of seconds) to accomplish. It is possible to control real-time gating with a fast tuning mechanism for photons and magnons.

The team used a new method involving energy-level tuning to quickly switch between magnonic or photonic states in a shorter time than either the magnon or the photon lifetimes. The period is only 10 to 100 nanoseconds.

Zhang said, “We begin by tuning the magnon and photon with an electric pulse so they have the same energy level.” “Then the information exchange between them continues until the electric pulse stops. This shifts the magnon’s energy level away from the photon.”

Zhang stated that this mechanism allows the team to control information flow, so it is either all in the photon, all in magnon, or somewhere in between. A novel device design allows nanosecond tuning of the magnetic field, which controls the magnon’s energy level. This provides for the coherent gate operation.

This research suggests a new direction in electromagnetics. Most importantly, the mechanism can manipulate magnonic states within the quantum regime. This opens opportunities for electromagnetics-based signal processing in quantum computing, communications, and sensing.

The DOE Office of Basic Energy Sciences partially supported this research. It was published in Physical Review Letters in a paper titled “Coherent gates operations in hybrid magnonics.” The authors include Jing Xu and Changchun Zhong, Xu Han, Dafei Jiang, and Xu Han.