by Riko Seibo
Tokyo, Japan (SPX) Apr 24, 2024
Researchers at Tohoku University and the Japan Atomic Energy Agency have made significant progress in understanding and manipulating the quantum metric-a geometric description of electronic states in magnetic materials under normal conditions.
The team has detected the quantum metric as an electric signal, separate from standard electrical conduction, showcasing a novel aspect of quantum physics. This discovery could lead to the creation of advanced spintronic devices that operate based on unconventional conduction methods introduced by the quantum metric.
Published in Nature Physics on April 22, 2024, the research investigates non-Ohmic electric conduction, a phenomenon where the current does not respond in direct proportion to voltage as described by Ohm's law. By exploring quantum mechanics, specifically the quantum metric, researchers can design materials that exhibit non-Ohmic conduction, a critical step for next-generation electronic devices.
The quantum metric concept, influenced by the 'metric' in general relativity, describes how space-time geometry is altered by gravity. Similarly, understanding the quantum metric in materials helps in designing and manipulating electronic properties at the quantum level.
The study utilized a thin-film heterostructure made from Mn3Sn and Pt, which revealed unique magnetic interactions. When subjected to a magnetic field, the material demonstrated a controlled second-order Hall effect-a type of non-Ohmic conduction where the voltage changes in relation to the square of the applied current.
Lead author Jiahao Han explains, "Our experiments show that the second-order Hall effect stems from the interaction between the quantum metric and the specific magnetic texture of the Mn3Sn/Pt interface. This interaction can be tuned using spintronic techniques, allowing us to manipulate these properties effectively at room temperature."
Yasufumi Araki, a key theorist in the team, emphasized the importance of the quantum metric in connecting experimental material properties with theoretical physics models. He expressed optimism that this experimental approach to the quantum metric would bolster theoretical research.
Shunsuke Fukami, the project's principal investigator, noted the transformative implications of their findings: "Previously, the quantum metric was considered a fixed property, much like aspects of the universe. Our results challenge this view, opening possibilities for developing devices like rectifiers and detectors."
Research Report:Room-temperature flexible manipulation of the quantum-metric structure in a topological chiral antiferromagnet
Related Links
Tohoku University
Understanding Time and Space