An inductor, one of the most fundamental circuit elements in modern electronic devices, generates a voltage proportional to the time derivative of the input current1. Conventional inductors typically consist of a helical coil and induce a voltage as a counteraction to time-varying magnetic flux penetrating the coil, following Faraday's law of electromagnetic induction. The magnitude of this conventional inductance is proportional to the volume of the inductor's coil, which hinders the miniaturization of inductors2. Here, we demonstrate an inductance of quantum-mechanical origin3, generated by the emergent electric field induced by current-driven dynamics of spin helices in a magnet. In microscale rectangular magnetic devices with nanoscale spin helices, we observe a typical inductance as large as -400 nanohenry, comparable in magnitude to that of a commercial inductor, but in a volume about a million times smaller. The observed inductance is enhanced by nonlinearity in current and shows non-monotonous frequency dependence, both of which result from the current-driven dynamics of the spin-helix structures. The magnitude of the inductance rapidly increases with decreasing device cross-section, in contrast to conventional inductors. Our findings may pave the way to microscale, simple-shaped inductors based on emergent electromagnetism related to the quantum-mechanical Berry phase.

中文翻译：

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螺旋自旋磁铁中的涌现电磁感应

电感器是现代电子设备中最基本的电路元件之一，它产生与输入电流的时间导数成比例的电压1。传统电感器通常由螺旋线圈组成，并根据法拉第电磁感应定律感应电压，以抵消穿透线圈的时变磁通量。这种传统电感的大小与电感线圈的体积成正比，这阻碍了电感的小型化2。在这里，我们展示了一种量子力学起源的电感，它是由磁体中自旋螺旋的电流驱动动力学引起的涌现电场产生的。在具有纳米级自旋螺旋的微米级矩形磁性器件中，我们观察到典型的电感高达 -400 纳亨，量级与商用电感器相当，但体积小约一百万倍。观察到的电感因电流的非线性而增强，并显示出非单调的频率依赖性，这两者都是由自旋螺旋结构的电流驱动动力学引起的。与传统电感相比，电感的大小随着器件横截面的减小而迅速增加。我们的研究结果可能为基于与量子力学贝里相相关的涌现电磁学的微型、简单形状的电感器铺平道路。与传统电感相比，电感的大小随着器件横截面的减小而迅速增加。我们的研究结果可能为基于与量子力学贝里相相关的涌现电磁学的微型、简单形状的电感器铺平道路。与传统电感相比，电感的大小随着器件横截面的减小而迅速增加。我们的研究结果可能为基于与量子力学贝里相相关的涌现电磁学的微型、简单形状的电感器铺平道路。