New technology paves the way for enhanced data processing in both classical and quantum regimes.
Most of us passing through gates every day — points of entry and exit to a place like a subway, park, or garden. Electronics have gates too. These regulate the flow of data from one point to another through an electrical signal. Unlike a park gate, these gates need control of their opening and closing several times faster than the blink of an eye.
Researchers at the University of Chicago’s Pritzker School of Molecular Engineering and the U.S. Department of Energy’s (DOE) Argonne National Laboratory have invented a unique way of managing gate operation effectively with a form of data processing called electromagnonics. Their crucial discovery enables real-time control of data transfer between magnons and microwave photons. And it could allow the new generation of the quantum signal and traditional electronic devices that can be utilized in numerous applications such as quantum networking, signal switching, and low-power computing.
Microwave photons are fundamental particles creating the electromagnetic waves used in, for example, wireless communications. Magnons are the particle-like representatives of “spin waves.” That is wave-like disturbances in an organized array of microscopically aligned spins that occur in specific magnetic materials.
“Many study societies are connecting various types of data carriers for information processing,” said Xufeng Zhang, a researcher in the Center for Nanoscale Materials, a DOE Office of Science User Facility at Argonne. “Such hybrid systems would allow practical utilization that are not feasible with data carriers of a single type.”
“Signal processing that pairs microwaves and spin waves is a high-wire act,” added Zhang. “The signal need to remain combined despite distributions and other external factors threatening to force the system into incoherence.”
Combined gate operation (command over on, off, and span of the magnon-photon interaction) has been a long-sought-after purpose in hybrid magnonic systems. In principle, this can be accomplished by a quick-tuning of energy levels between the photon and magnon. Though, such tuning has depended on switching the geometric configuration of the device. That typically needs much longer than the magnon lifetime — on the scale of 100 nanoseconds (one-hundred billionths of a second). This necessity of a quick tuning mechanism for interacting magnons and photons has made it impossible to perform any real-time gating control.
Using a new method comprising energy-level tuning, the group was able to quickly switch between magnonic and photonic states over a duration shorter than the magnon or photon lifetimes. This session is a mere 10 to 100 nanoseconds.
“We begin by tuning the photon and magnon with an electric pulse so that they have the identical energy level,” said Zhang. “Then, the data transfer starts between them and lasts until the electric pulse is turned off, which turns the energy level of the magnon away from that of the photon.”
By this mechanism, Zhang said, the group can command the flow of data so that it is all in the photon or all in the magnon or someplace in between. This is made feasible by a new device configuration that allows nanosecond tuning of a magnetic field that commands the magnon energy level. This tunability enables the desired combined gate operation.
This study leads to a new path for electromagnetics. Most importantly, the illustrated mechanism not only operates in the traditional electronics régime but can also be easily used for manipulating magnonic states in the quantum régime. This uncovers possibilities for electromagnonics-based signal processing in quantum computing, communications, and sensing.
This study was partially backed by the DOE Office of Basic Energy Sciences. It was published in Physical Review Letters, in a paper titled “Coherent gate operations in hybrid magnonics.”
Reference: “Coherent Gate Operations in Hybrid Magnonics” by Xu Han, Dafei Jin, Xufeng Zhang, Jing Xu, Changchun Zhong, and Liang Jiang, 21 May 2021, Physical Review Letters.