Researchers in South Korea have created magnetic nanohelices that may management electron spin at room temperature.
Spintronics, additionally referred to as spin electronics, explores info processing through the use of the intrinsic angular momentum (spin) of electrons somewhat than solely their electrical cost. By tapping spin, researchers goal to construct information storage and logic gadgets that function quicker and eat much less vitality. A significant impediment has been creating supplies that may exactly and reliably set the path of electron spin.
In a major step for spin nanotechnology, researchers led by Professor Younger Keun Kim of Korea College and Professor Ki Tae Nam of Seoul Nationwide College have created magnetic nanohelices that management electron spin. The method makes use of chiral magnetic supplies to control spin at room temperature, and the findings have been revealed in Science.
“These nanohelices obtain spin polarization exceeding ~80% — simply by their geometry and magnetism,” said Professor Younger Keun Kim of Korea College, a co-corresponding creator of the research. He additional emphasised, “This can be a uncommon mixture of structural chirality and intrinsic ferromagnetism, enabling spin filtering at room temperature with out complicated magnetic circuitry or cryogenics, and offers a brand new method to engineer electron habits utilizing structural design.”
Engineering Chirality on the Nanoscale
The analysis workforce efficiently fabricated left- and right-handed chiral magnetic nanohelices by electrochemically controlling the metallic crystallization course of. A important innovation concerned introducing hint quantities of chiral natural molecules, akin to cinchonine or cinchonidine, which guided the formation of helices with exactly outlined handedness—a feat not often achieved in inorganic techniques.
Additionally, the workforce experimentally demonstrated that when these nanohelices exhibit a right-handedness, they preferentially permit one path of spin to cross, whereas the alternative spin can’t. The above marks the invention of a 3D inorganic helical nanostructure able to electron spin management.
“Chirality is well-understood in natural molecules, the place the handedness of a construction usually determines its organic or chemical perform,” famous Professor Ki Tae Nam of Seoul Nationwide College, additionally a co-corresponding creator. “However in metals and inorganic supplies, controlling chirality throughout synthesis is extraordinarily tough, particularly on the nanoscale. The fact that we could program the direction of inorganic helices simply by adding chiral molecules is a breakthrough in materials chemistry.”
Measuring and Applying Spin Control
To confirm the chirality of nanohelices, the researchers developed an electromotive force (emf)-based chirality evaluation method and measured the emf generated by the helices under rotating magnetic fields. The left- and right-handed helices produced opposite emf signals, allowing for quantitative verification of chirality even in materials that do not strongly interact with light.
The research team also found that the magnetic material itself, through its inherent magnetization (spin alignment), enables long-distance spin transport at room temperature. This effect, maintained by strong exchange energy, is constant regardless of the angle between the chiral axis and the spin injection direction, and was not observed in non-magnetic nanohelices of the same scale. The above marks the first measurement of asymmetric spin transport in a relatively macro-scaled chiral body. The team also demonstrated a solid-state device that showed chirality-dependent conduction signals, paving the way for practical spintronic applications.
Professor Kim highlighted the potential impact: “We believe this system could become a platform for chiral spintronics and architecture of chiral magnetic nanostructures”. This work represents a powerful convergence of geometry, magnetism, and spin transport, built from scalable, inorganic materials. The ability to control the handedness (left/right) and even the number of strands (double, multiple helices) using this versatile electrochemical method is expected to contribute significantly to new application areas.
Reference: “Spin-selective transport through chiral ferromagnetic nanohelices” by Yoo Sang Jeon, Eunjin Jeong, Sang Won Im, Min Jun Ko, Jin Seo Lee, Jun Hwan Moon, Min Hyeok Lee, Jeong Kyu Lee, Sung Jong Yoo, Ki Tae Nam and Young Keun Kim, 4 September 2025, Science.
DOI: 10.1126/science.adx5963
Funding: National Research Foundation of Korea
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