Acharya Gokul, Neupane Bimal, Hsu Chia-Hsiu, Yang Xian P, Graf David, Choi Eun Sang, Pandey Krishna, Nabi Md Rafique Un, Chhetri Santosh Karki, Basnet Rabindra, Rahman Sumaya, Wang Jian, Hu Zhengxin, Da Bo, Churchill Hugh O H, Chang Guoqing, Hasan M Zahid, Wang Yuanxi, Hu Jin
Department of Physics, University of Arkansas, Fayetteville, AR, 72701, USA.
Department of Physics, University of North Texas, Denton, TX, 76205, USA.
Adv Mater. 2024 Nov;36(48):e2410655. doi: 10.1002/adma.202410655. Epub 2024 Oct 11.
Magnetotransport, the response of electrical conduction to external magnetic field, acts as an important tool to reveal fundamental concepts behind exotic phenomena and plays a key role in enabling spintronic applications. Magnetotransport is generally sensitive to magnetic field orientations. In contrast, efficient and isotropic modulation of electronic transport, which is useful in technology applications such as omnidirectional sensing, is rarely seen, especially for pristine crystals. Here a strategy is proposed to realize extremely strong modulation of electron conduction by magnetic field which is independent of field direction. GdPS, a layered antiferromagnetic semiconductor with resistivity anisotropies, supports a field-driven insulator-to-metal transition with a paradoxically isotropic gigantic negative magnetoresistance insensitive to magnetic field orientations. This isotropic magnetoresistance originates from the combined effects of a near-zero spin-orbit coupling of Gd-based half-filling f-electron system and the strong on-site f-d exchange coupling in Gd atoms. These results not only provide a novel material system with extraordinary magnetotransport that offers a missing block for antiferromagnet-based ultrafast and efficient spintronic devices, but also demonstrate the key ingredients for designing magnetic materials with desired transport properties for advanced functionalities.
磁输运，即导电对外部磁场的响应，是揭示奇异现象背后基本概念的重要工具，并且在实现自旋电子学应用中起着关键作用。磁输运通常对磁场方向敏感。相比之下，电子输运的高效且各向同性调制在诸如全向传感等技术应用中很有用，但却很少见，尤其是对于原始晶体而言。在此，我们提出一种策略，以实现与磁场方向无关的、由磁场对电子传导的极强调制。GdPS是一种具有电阻率各向异性的层状反铁磁半导体，它支持场驱动的绝缘体到金属的转变，具有反常的各向同性巨大负磁阻，且对磁场方向不敏感。这种各向同性磁阻源于基于Gd的半填充f电子系统的近零自旋轨道耦合与Gd原子中强的在位f-d交换耦合的综合效应。这些结果不仅提供了一种具有非凡磁输运的新型材料体系，为基于反铁磁体的超快高效自旋电子器件提供了缺失的环节，而且还展示了设计具有用于先进功能的所需输运特性的磁性材料的关键要素。
