论文标题
浆果 - 透过的单极的缩放主导了大型线性阳性磁场
Scaling of Berry-curvature monopole dominated large linear positive magnetoresistance
论文作者
论文摘要
线性阳性磁阻(LPMR)是拓扑材料中广泛观察到的现象,这对于拓扑旋转的潜在应用有望。但是,其机制仍然模棱两可,因此无法控制的效果。在这里,我们报告了一个定量缩放模型,该模型将LPMR与浆果曲率相关联,基于铁磁Weyl Semimetal cos2,在2 Kelvin和9 Tesla的最大LPMR中,在已知的磁性拓扑半学中,其最大500%。在该系统中,理论计算揭示了在费米水平附近存在的Weyl节点的质量,用作浆果 - 透明质的单翼和低效应的质量载体。基于Weyl图,我们提出了一个关系\ [\ text {mr} = \ frac {e} {\ hbar} b {{ω} _ {\ text {f text {f}}} \],b是应用的磁场,be {在费米表面附近,并进一步将温度因子引入MR/B斜率(MR每个单位场)和异常的霍尔电导率,这建立了模型与实验测量之间的联系。在K空间浆果曲率和真实空间磁场的合作下,证明了载体线性放慢速度的清晰图片,即LPMR效应。我们的研究不仅提供了第一次浆果曲率诱导LPMR的实验证据,而且还促进了大型浆果膜的MR在拓扑DIRAC/WEYL系统中的共同理解和功能设计,用于磁传感或信息存储。
The linear positive magnetoresistance (LPMR) is a widely observed phenomenon in topological materials, which is promising for potential applications on topological spintronics. However, its mechanism remains ambiguous yet and the effect is thus uncontrollable. Here, we report a quantitative scaling model that correlates the LPMR with the Berry curvature, based on a ferromagnetic Weyl semimetal CoS2 that bears the largest LPMR of over 500% at 2 Kelvin and 9 Tesla, among known magnetic topological semimetals. In this system, masses of Weyl nodes existing near the Fermi level, revealed by theoretical calculations, serve as Berry-curvature monopoles and low-effective-mass carriers. Based on the Weyl picture, we propose a relation \[\text{MR}=\frac{e}{\hbar }B{{Ω}_{\text{F}}}\], with B being the applied magnetic field and \[{{Ω}_{\text{F}}}\] the average Berry curvature near the Fermi surface, and further introduce temperature factor to both MR/B slope (MR per unit field) and anomalous Hall conductivity, which establishes the connection between the model and experimental measurements. A clear picture of the linearly slowing down of carriers, i.e., the LPMR effect, is demonstrated under the cooperation of the k-space Berry curvature and real-space magnetic field. Our study not only provides an experimental evidence of Berry curvature induced LPMR for the first time, but also promotes the common understanding and functional designing of the large Berry-curvature MR in topological Dirac/Weyl systems for magnetic sensing or information storage.