A recent study has advanced the understanding of magnonics by showing how magnons can interact nonlinearly, marking a critical step towards faster and more stable computing technologies.
- If computers used ripples in magnetic fields, called magnons, to encode and process information, the result would be devices with potential memory speed on the order of billionths of a second.
- California NanoSystems Institute at UCLA, the use of terahertz lasers suggests potential synergy with a technology growing in maturity.
“Terahertz technology itself has reached the point where we can talk about a second technology that relies on it,” she said. “It makes sense to do this type of nonlinear control in a band where we have lasers and detectors that can be put on a chip. Now is the time to really push forward because we have both the technology and an interesting theoretical framework for looking at interactions among magnons.”
Unveiling Nonlinear Interactions in Magnonics
The researchers applied laser pulses to a 2-millimeter-thick plate made from a carefully chosen alloy containing yttrium, a metal found in LEDs and radar technology. In some experiments, a second terahertz laser was used in a coordinated way that paradoxically added energy but helped stabilize samples.
A magnetic field was applied to the yttrium in a specific fashion that allowed for only two types of magnon. The investigators were able to drive either type of magnon individually or both at the same time by rotating the sample to certain angles relative to the lasers. They were able to measure the interactions between the two types and found that they could cause nonlinear responses.
“Clearly demonstrating this nonlinear interaction would be important for any sort of application based on signal processing,” said co-author Jonathan Curtis, a UCLA postdoctoral researcher in the NarangLab. “Mixing signals like this could allow us to convert between different magnetic inputs and outputs, which is what you need for a device that relies on manipulating information magnetically.”
Narang said that trainees are vital to the current study, as well as the larger project.
“This is a really hard, multiyear endeavor with a lot of pieces,” she said. “What’s the right system and how do we go about working with it? How do we think about making predictions? How do we limit the system so it’s behaving as we want it to? We wouldn’t be able to do this without talented students and postdocs.”
For more on this research, see How Invisible Light Is Shaping the Future of High-Speed Computing.
References:
- “Terahertz field-induced nonlinear coupling of two magnon modes in an antiferromagnet” by Zhuquan Zhang, Frank Y. Gao, Jonathan B. Curtis, Zi-Jie Liu, Yu-Che Chien, Alexander von Hoegen, Man Tou Wong, Takayuki Kurihara, Tohru Suemoto, Prineha Narang, Edoardo Baldini and Keith A. Nelson, 31 January 2024, Nature Physics.
DOI: 10.1038/s41567-024-02386-3 - “Terahertz-field-driven magnon upconversion in an antiferromagnet” by Zhuquan Zhang, Frank Y. Gao, Yu-Che Chien, Zi-Jie Liu, Jonathan B. Curtis, Eric R. Sung, Xiaoxuan Ma, Wei Ren, Shixun Cao, Prineha Narang, Alexander von Hoegen, Edoardo Baldini and Keith A. Nelson, 23 January 2024, Nature Physics.
DOI: 10.1038/s41567-023-02350-7
The study includes MIT chemistry professor Keith Nelson and UT Austin physics professor Edoardo Baldini, along with the UCLA team led by Narang, which was supported by the Quantum Science Center, a Department of Energy National Quantum Information Science Research Center headquartered at Oak Ridge National Laboratory. The study was primarily supported by the Department of Energy as well as the Alexander von Humboldt Foundation, the Gordon and Betty Moore Foundation, the John Simon Guggenheim Memorial Foundation and the Japan Society for the Promotion of Science — all of which provide ongoing support for the collaboration.
- “Terahertz field-induced nonlinear coupling of two magnon modes in an antiferromagnet” by Zhuquan Zhang, Frank Y. Gao, Jonathan B. Curtis, Zi-Jie Liu, Yu-Che Chien, Alexander von Hoegen, Man Tou Wong, Takayuki Kurihara, Tohru Suemoto, Prineha Narang, Edoardo Baldini and Keith A. Nelson, 31 January 2024, Nature Physics.