带隙节线半金属中由能带几何激活的磁场驱动输运
Magnetic-field-activated transport from band geometry in gapped nodal-line semimetals
- Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México（墨西哥国立自治大学核科学研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文发展非微扰半经典理论，揭示轨道磁矩重构费米面并激活零场缺失的内禀霍尔电流，提出磁场激活的几何输运作为节线半金属的特征标志。
AI中文摘要：
我们发展了一种针对带隙节线半金属中磁输运的非微扰半经典理论，保留了贝里曲率和轨道磁矩修正对磁场的完整依赖。从一个最小二带模型出发，我们推导了内禀霍尔响应和耗散费米面电导率的精确表达式，在半经典范围内对磁场所有阶次均有效。我们表明，轨道磁矩重构了几何活跃的费米面，打破了节线几何所施加的方位角抵消，从而激活了在零磁场下不存在的内禀霍尔电流。霍尔响应表现出对化学势的显著非单调依赖以及强非线性的磁场演化，反映了几何活跃态在节线环周围的重新分布。我们进一步证明，费米面电导率在弱场极限下恢复传统的德鲁德行为，同时获得二次方乃至最终非微扰的磁场修正，以及场致输运各向异性，后者在中等磁场下产生可测量的平面霍尔效应。当费米能级靠近节线环时，内禀和耗散响应均显著增强，此时贝里曲率和轨道磁矩最大。我们的结果将磁场激活的几何输运确定为节线半金属的特征标志，并为描述超越微扰磁场展开的磁输运提供了统一框架，同时提供了轨道磁矩物理的实验可探测特征。
英文摘要：
We develop a nonperturbative semiclassical theory of magnetotransport in gapped nodal-line semimetals, retaining the full magnetic-field dependence of Berry-curvature and orbital-magnetic-moment corrections. Starting from a minimal two-band model, we derive exact expressions for both the intrinsic Hall response and the dissipative Fermi-surface conductivity, valid to all orders in the magnetic field within the semiclassical regime. We show that the orbital magnetic moment reconstructs the geometrically active Fermi surface, breaking the azimuthal cancellation imposed by the nodal-line geometry and thereby activating an intrinsic Hall current that is absent at zero magnetic field. The Hall response exhibits a pronounced nonmonotonic dependence on the chemical potential and a strongly nonlinear magnetic-field evolution, reflecting the redistribution of geometrically active states around the nodal ring. We further demonstrate that the Fermi-surface conductivities recover the conventional Drude behavior in the weak-field limit, while acquiring quadratic and ultimately nonperturbative magnetic-field corrections together with a field-induced transport anisotropy that gives rise to a measurable planar Hall effect at intermediate fields. Both the intrinsic and dissipative responses are strongly enhanced when the Fermi level lies close to the nodal ring, where Berry curvature and orbital magnetic moment are largest. Our results identify magnetic-field-activated geometric transport as a characteristic signature of nodal-line semimetals and provide a unified framework for describing magnetotransport beyond perturbative magnetic-field expansions, together with experimentally accessible signatures of orbital-magnetic-moment physics.
