New helical magnet memory technology, outlined by researchers, enables high-density, stable storage with minimal crosstalk, signaling a major advancement in non-volatile memory devices. Credit: SciTechDaily.com
Researchers have developed a new magnet-based memory device using helical magnets, promising high-density, non-volatile storage without magnetic field crosstalk.
This breakthrough offers a sustainable solution to current challenges in information storage, with potential for large-scale integration and high durability.
A team of scientists has proposed a new concept for magnet-based memory devices, which might revolutionize information storage devices owing to their potential for large-scale integration, non-volatility, and high durability.
Details of their findings were published in the journal Nature Communications.
Spintronic devices, represented by magnetic random access memory (MRAM), utilize the magnetization direction of ferromagnetic materials to memorize information. Because of their non-volatility and low energy consumption, spintronic devices will likely play a pivotal role in future information storage components.
Challenges and New Solutions
However, ferromagnet-based spintronics devices have a potential pitfall. Ferromagnets generate magnetic fields around them, which affect nearby ferromagnets. In an integrated magnetic device, this results in crosstalk between magnetic bits, which will limit the magnetic memory density.
The research team, which comprised Hidetoshi Masuda, Takeshi Seki, Yoshinori Onose, and others from Tohoku University’s Institute for Materials Research, and Jun-ichiro Ohe from Toho University, demonstrated that magnetic materials called helical magnets can be utilized for a magnetic memory device, which should resolve the magnetic field problem.
Concept of the helimagnet-based memory devices. The directions of the atomic magnetic moments, depicted by the colored allows, are arranged into a spiral. Chirality, the right- and left-handed rotation direction of the spiral, is utilized to memorize information. Credit: Masuda et. al.
Helical Magnets and Chirality Memory
In helical magnets, the directions of the atomic magnetic moments are ordered in a spiral. The right- or left-handedness of the spiral, called chirality, could be utilized to memorize the information. The magnetic fields induced by each atomic magnetic moment cancel each other out, so the helical magnets do not generate any macroscopic magnetic field. “The memory devices based on the handedness of the helimagnets, free from the crosstalk among bits, could pave a new pathway for improving the memory density,” says Masuda.
The research team demonstrated that the chirality memory can be written and read out at room temperature. They fabricated epitaxial thin films of a room-temperature helimagnet MnAu2 and demonstrated the switching of chirality (right- and left-handedness of the spiral) by the electric current pulses under magnetic fields. Furthermore, they fabricated a bilayer device composed of MnAu2 and Pt (platinum) and demonstrated that the chirality memory can be read out as a resistance change, even without magnetic fields.
Future Implications
“We have uncovered the potential capability of chirality memory in helical magnets for next-generation memory devices; it may offer high-density, non-volatile, and highly stable memory bits,” adds Masuda. “This will hopefully lead to future storage devices with ultrahigh information density and high reliability.”
Reference: “Room temperature chirality switching and detection in a helimagnetic MnAu2 thin film” by Hidetoshi Masuda, Takeshi Seki, Jun-ichiro Ohe, Yoichi Nii, Hiroto Masuda, Koki Takanashi and Yoshinori Onose, 7 March 2024, Nature Communications.
