Kitaori Aki, White Jonathan S, Ukleev Victor, Peng Licong, Nakajima Kiyomi, Kanazawa Naoya, Yu Xiuzhen, Ōnuki Yoshichika, Tokura Yoshinori
Institute of Engineering Innovation, The University of Tokyo, Tokyo, 113-0032 Japan.
Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656 Japan.
Commun Phys. 2024;7(1):159. doi: 10.1038/s42005-024-01656-z. Epub 2024 May 20.
In helimagnetic metals, ac current-driven spin motions can generate emergent electric fields acting on conduction electrons, leading to emergent electromagnetic induction (EEMI). Recent experiments reveal the EEMI signal generally shows a strongly current-nonlinear response. In this study, we investigate the EEMI of TbSb, a short-period helimagnet. Using small angle neutron scattering we show that TbSb hosts highly disordered helimagnetism with a distribution of spin-helix periodicity. The current-nonlinear dynamics of the disordered spin helix in TbSb indeed shows up as the nonlinear electrical resistivity (real part of ac resistivity), and even more clearly as a nonlinear and huge EEMI (imaginary part of ac resistivity) response. The magnitude of the EEMI reaches as large as several tens of μH for Tb5Sb3 devices on the scale of several tens of μm, originating to noncollinear spin textures possibly even without long-range helimagnetic order.
在螺旋磁性金属中，交流电流驱动的自旋运动会产生作用于传导电子的新兴电场，从而导致新兴电磁感应（EEMI）。最近的实验表明，EEMI信号通常表现出强烈的电流非线性响应。在本研究中，我们研究了短周期螺旋磁体TbSb的EEMI。通过小角中子散射，我们表明TbSb具有高度无序的螺旋磁性，自旋螺旋周期存在分布。TbSb中无序自旋螺旋的电流非线性动力学确实表现为非线性电阻率（交流电阻率的实部），甚至更明显地表现为非线性且巨大的EEMI（交流电阻率的虚部）响应。对于几十微米尺度的Tb5Sb3器件，EEMI的幅度高达几十微亨，这可能源于甚至没有长程螺旋磁序的非共线自旋纹理。
