标题： 由磁场梯度驱动的非线性非互易电子电导率 显示英文标题

标题： Nonlinear nonreciprocal electronic conductivity driven by magnetic field gradients

摘要： 我们理论提出，在外加空间梯度磁场的情况下，中心对称的磁性系统中会出现非线性非互易电导率。 关键本质在于梯度磁场下出现的磁性环形偶极矩，这破坏了空间反演和时间反演对称性。 通过分析二维系统上的一个最小紧束缚模型，我们表明，由梯度场产生的磁性环形偶极矩与亚晶格相关的反对称自旋-轨道相互作用之间的有效耦合在诱导非线性非互易输运中起着重要作用。 我们还通过提出一个实验装置来讨论在实际材料中观察非线性非互易电导率的有利情况，以激发这些发现。 显示英文摘要

摘要： We theoretically propose the emergence of nonlinear nonreciprocal conductivity in centrosymmetric paramagnetic systems when a spatially gradient magnetic field is externally applied. The key essence lies in the appearance of magnetic toroidal dipole moment under the gradient field that breaks both spatial inversion and time-reversal symmetries. By analyzing a minimal tight-binding model on a two-dimensional system, we show that an effective coupling between the magnetic toroidal dipole moment arising from the gradient field and sublattice-dependent antisymmetric spin-orbit interaction plays an important role in inducing the nonlinear nonreciprocal transport. We also discuss the favorable situation to observe the nonlinear nonreciprocal conductivity in real materials by presenting an experimental setup in order to stimulate the findings.