Huang Shiming, Zhu Lianying, Zhao Yongxin, Watanabe Kenji, Taniguchi Takashi, Xiao Jie, Wang Le, Mei Jiawei, Huang Huolin, Zhang Feng, Wang Maoyuan, Fu Deyi, Zhang Rong
Department of Physics, Engineering Research Center for Micro-Nano Optoelectronic Materials and Devices of Ministry of Education, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen, China.
National Institute for Materials Science, Tsukuba, Japan.
Nat Commun. 2025 Mar 24;16(1):2866. doi: 10.1038/s41467-025-58224-4.
Information technology has a great demand for magnetoresistance (MR) sensors with high sensitivity and wide-temperature-range operation. It is well known that space charge inhomogeneity in graphene (Gr) leads to finite MR in its pristine form, and can be enhanced by increasing the degree of spatial disorder. However, the enhanced MR usually diminishes drastically as the temperature decreases. Here, by stacking a van der Waals ferromagnet FeGeTe (FGT) on top of graphene to form an FGT/Gr heterostructure, we demonstrate a positive MR of up to ~9400% under a magnetic field of 9 T at room temperature (RT), an order of magnitude larger MR compared to pure graphene. More strikingly, the giant MR of the FGT/Gr heterostructure sustains over a wide temperature range from RT down to 4 K. Both control experiments and DFT calculations show that the enhanced MR originates from spin-dependent orbital coupling between FGT and graphene, which is temperature insensitive. Our results open a new route for realizing high-sensitivity and wide-temperature-range MR sensors.
信息技术对具有高灵敏度和宽温度范围操作的磁阻（MR）传感器有很大需求。众所周知，石墨烯（Gr）中的空间电荷不均匀性导致其原始形式存在有限的磁阻，并且可以通过增加空间无序度来增强。然而，随着温度降低，增强的磁阻通常会急剧减小。在此，通过在石墨烯顶部堆叠范德华铁磁体FeGeTe（FGT）以形成FGT/Gr异质结构，我们展示了在室温（RT）下9 T磁场下高达约9400%的正磁阻，与纯石墨烯相比，磁阻大一个数量级。更引人注目的是，FGT/Gr异质结构的巨大磁阻在从室温到4 K的宽温度范围内都能保持。对照实验和密度泛函理论（DFT）计算均表明，增强的磁阻源于FGT与石墨烯之间的自旋相关轨道耦合，这种耦合对温度不敏感。我们的结果为实现高灵敏度和宽温度范围的磁阻传感器开辟了一条新途径。
