发表机构
Indian Association for the Cultivation of Science; S. N. Bose National Centre for Basic Sciences; Uppsala University; UGC-DAE Consortium for Scientific Research, Kolkata Centre; Deutsches Elektronen-Synchrotron DESY; Diamond Light Source; ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory; Indian Institute of Technology Kharagpur（印度科学培养协会; S.N. 玻色基础科学国家中心; 乌普萨拉大学; UGC-DAE 科学研究联盟加尔各答中心; 德国电子同步加速器研究所; 钻石光源; ISIS 中子和缪子源，科学与技术设施委员会，卢瑟福阿普尔顿实验室; 印度理工学院卡拉格普尔分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过实验和理论计算，发现MnP单晶在低温强磁场下呈现近800%的线性正磁电阻，源于半狄拉克能带形成的小费米口袋进入量子极限区域，为理解复杂磁性材料中的量子磁电阻提供了微观机制。
AI 中文摘要
拓扑和磁性材料中的大线性正磁电阻（LPMR）一直是一个激烈争论的话题，尤其是在非共线自旋系统中，自旋相关的散射使电荷输运变得复杂。磷化锰（MnP）是一种具有多种场致磁相变的螺旋磁性二元磷化物，为研究复杂磁性与电子拓扑之间的相互作用提供了一个有用的平台。在此，我们展示了高质量MnP单晶中相依赖磁输运的综合实验和理论研究。霍尔测量揭示了在高温下由斜散射主导的反常霍尔效应，以及在非共线扇形（FAN）和低温螺旋（SCR）相中有限的拓扑霍尔效应。在低温下，我们观察到大的、不饱和的LPMR，在4 K和15 T时达到近800%，并且在场极化铁磁（FM2）态中具有显著的线性场依赖性。第一性原理计算揭示了Y点处一个强各向异性的半狄拉克型能带，该能带从SCR态到FAN态和FM2态逐渐接近费米能级。我们的分析表明，由此产生的小费米口袋可以在实验可达到的磁场下进入极端量子极限区域，为在Abrikosov量子磁电阻理论框架内观察到的LPMR提供了微观解释。
英文摘要
Large linear positive magnetoresistance (LPMR) in topological and magnetic materials remains a subject of intense debate, particularly in noncollinear spin systems where spin-dependent scattering complicates charge transport. Manganese phosphide (MnP), a helimagnetic binary pnictide with multiple field-induced magnetic transitions, provides a useful platform to investigate the interplay between complex magnetism and electronic topology. Here, we present a comprehensive experimental and theoretical investigation of phase-dependent magnetotransport in high-quality MnP single crystals. Hall measurements reveal an anomalous Hall effect dominated by skew scattering at high temperatures and a finite topological Hall effect in the noncollinear fan (FAN) and low-temperature screw (SCR) phases. At low temperatures, we observe a large, non-saturating LPMR reaching nearly 800 percent at 4 K and 15 T, with a pronounced linear field dependence in the field-polarized ferromagnetic (FM2) state. First-principles calculations reveal a strongly anisotropic semi-Dirac-like band at the Y point that progressively approaches the Fermi level from the SCR to FAN and FM2 states. Our analysis indicates that the resulting small Fermi pocket can access the extreme quantum-limit regime at experimentally accessible fields, providing a microscopic framework for the observed LPMR within Abrikosov's quantum magnetoresistance theory.
Comments15 pages, 9 figures
