标题： 磁场诱导的LaTiO$_3$/SrTiO$_3$界面非线性输运 显示英文标题

标题： Magnetic Field Induced Nonlinear Transport in LaTiO$_3$/SrTiO$_3$ Interfaces

摘要： 受最近在外部平面磁场下对自旋轨道耦合电子气体在(111) LaTiO$_3$/SrTiO$_3$界面的非线性纵向电阻的实验测量 [G. Tuvia\emph{等.}, Phys. Rev. Lett. 132, 146301 (2024)] 的启发，我们基于对Wigner分布函数的量子动力学方程的分析，提出了一个非线性电子输运理论。具体来说，我们在任意磁场均值下评估电流密度的二次谐波的磁场依赖性。在小磁场下，二次谐波的大小随磁场线性增加。随着磁场进一步增加，二次谐波响应达到最大值。我们发现峰的位置及其宽度强烈依赖于由于无序引起的弛豫率。重要的是，我们发现当磁场达到某个临界值时，电流的非线性贡献的方向可以完全反转。 显示英文摘要

摘要： Motivated by the recent experimental measurements of the nonlinear longitudinal resistance of the spin-orbit coupled electron gas in the (111) LaTiO$_3$/SrTiO$_3$ interfaces under external in-plane magnetic field [G. Tuvia \emph{et al.}, Phys. Rev. Lett. 132, 146301 (2024)], we formulate a theory of nonlinear electronic transport based on the analysis of the quantum kinetic equation for the Wigner distribution function. Specifically, we evaluate the magnetic field dependence of the second harmonic of the current density at arbitrary values of the magnetic field. The magnitude of the second harmonic increases linearly with the magnetic field at small fields. Upon further increase of the magnetic field, the second harmonic response reaches its maximum value. We find that the position of the peak and its width strongly depend on the relaxation rate due to disorder. Importantly, we discover that the direction of the nonlinear contribution to the current can be completely reversed when the magnetic field reaches a certain critical value.