标题： 非磁性金属中弱场下的通用和内在负纵向磁阻 显示英文标题

标题： Generic and intrinsic negative longitudinal magnetoresistance at weak fields in non-magnetic metals with inversion symmetry

摘要： 负纵向磁阻（NLMR）是指当驱动电场和外部磁场共线时，材料的电阻率降低的现象。 在半经典弱场范围内，非磁性金属的NLMR在存在大量贝里曲率（BC）的情况下被激活。 这将半经典NLMR的出现限制在非对称晶体结构的金属中，包括外尔半金属。 在这里，我们展示了一种以前未被发现的半经典NLMR机制，这种机制可以在强自旋-轨道耦合的非磁性金属中存在，即使晶体具有体反演对称性。 一个泽曼激活的BC直接与布洛赫电子的轨道运动耦合，产生一种与弛豫时间成正比的负MR，精确地类似于德鲁德电阻率。 重要的是，泽曼激活的BC是外部磁场强度的\emph{独立的}。 它与自旋-轨道耦合电子带的非抛物性程度有关。 我们证明，这种与Landé$g$因子无关的NLMR机制是普遍的，并且出现在\emph{全部}个中心对称点群中，并且可以在拓扑和常规导体中发生。 显示英文摘要

摘要： Negative longitudinal magnetoresistance (NLMR) is a decrease in the electrical resistivity of a material when the driving electric field and an external magnetic field are collinear. In the semiclassical weak field regime, the NLMR of non-magnetic metals is activated in the presence of substantial concentrations of Berry curvature (BC). This restricts the appearance of a semi-classical NLMR to metals with acentric crystalline arrangements, including Weyl semimetals. Here, we show a previously unidentified mechanism of semi-classical NLMR that can be present in strongly spin-orbit coupled non-magnetic metals even if the crystal possess bulk inversion symmetry. A Zeeman-activated BC directly couples to the orbital motion of Bloch electrons to generate a negative MR that scales with the relaxation time precisely as the Drude resistivity. Importantly, the Zeeman-activated BC is \emph{independent} of the external magnetic field strength. It is instead related to the degree of non-parabolicity of the spin-orbit coupled electronic bands. We show that this NLMR mechanism, which is independent of the Land\'e $g$-factor, is generic and appears in \emph{all} centrosymmetric point groups and can occur both in topological and conventional conductors.