Application of an electric stimulus to a material with a metal-insulator transition can trigger a large resistance change. Resistive switching from an insulating into a metallic phase, which typically occurs by the formation of a conducting filament parallel to the current flow, is a highly active research topic. Using the magneto-optical Kerr imaging, we found that the opposite type of resistive switching, from a metal into an insulator, occurs in a reciprocal characteristic spatial pattern: the formation of an insulating barrier perpendicular to the driving current. This barrier formation leads to an unusual N-type negative differential resistance in the current-voltage characteristics. We further demonstrate that electrically inducing a transverse barrier enables a unique approach to voltage-controlled magnetism. By triggering the metal-to-insulator resistive switching in a magnetic material, local on/off control of ferromagnetism is achieved using a global voltage bias applied to the whole device.

对具有金属-绝缘体转变的材料施加电刺激可以引发大的电阻变化。从绝缘相到金属相的电阻转换通常是通过形成与电流平行的导电丝而发生的，是一个高度活跃的研究课题。利用磁光克尔成像，我们发现相反类型的电阻切换（从金属到绝缘体）以相反的特征空间模式发生：形成垂直于驱动电流的绝缘势垒。这种势垒的形成导致电流-电压特性中出现异常的 N 型负微分电阻。我们进一步证明，电感应横向势垒可以实现电压控制磁性的独特方法。通过触发磁性材料中的金属到绝缘体电阻切换，使用施加到整个器件的全局电压偏置来实现铁磁性的局部开/关控制。