近日，法国洛林大学的Yuan Lu及其研究团队取得一项新进展。经过不懈努力，他们通过电磁化开关控制光的螺旋度。相关研究成果已于2024年3月27日在国际权威学术期刊《自然》上发表。

该研究团队证明光子学、电子学和自旋电子学各自学科之间缺失的环节是在室温和零外加磁场下，通过光子、电子和铁磁体之间的角动量传输在发光二极管中建立的。随着自旋-轨道转矩的产生，电荷电流也会产生自旋电流来电开关磁化。这种开关决定了注入到半导体中的载流子的自旋方向，其中从电子自旋到光子的角动量传输控制了发射光的圆偏振。具有非易失性磁化控制的自旋光子转换为无缝集成信息传输、处理和存储开辟了道路。

这项研究结果为下一代信息和通信技术(包括空间光数据传输)的电控超快圆偏振调制，和具有磁化动力学的自旋注入提供了实质性进展。在按比例缩小的结构或使用二维材料中，相同的工作原理将为自旋控制的单光子源的量子信息处理，以及实现自旋依赖的时间分辨光谱提供变革性机会。

据悉，控制发射光的强度和电荷电流是传输和处理信息的基础。相比之下，鲁棒的信息存储和磁性随机存取存储器，是利用载流子的自旋和铁磁体中的相关磁化来实现的。光子学、电子学和自旋电子学各自学科之间缺失的环节，是通过电控磁化来调制发射光的圆偏振，而不是其强度。

附：英文原文

Title: Controlling the helicity of light by electrical magnetization switching

Author: Dainone, Pambiang Abel, Prestes, Nicholas Figueiredo, Renucci, Pierre, Bouch, Alexandre, Morassi, Martina, Devaux, Xavier, Lindemann, Markus, George, Jean-Marie, Jaffrs, Henri, Lemaitre, Aristide, Xu, Bo, Stoffel, Mathieu, Chen, Tongxin, Lombez, Laurent, Lagarde, Delphine, Cong, Guangwei, Ma, Tianyi, Pigeat, Philippe, Vergnat, Michel, Rinnert, Herv, Marie, Xavier, Han, Xiufeng, Mangin, Stephane, Rojas-Snchez, Juan-Carlos, Wang, Jian-Ping, Beard, Matthew C., Gerhardt, Nils C., uti, Igor, Lu, Yuan

Issue&Volume: 2024-03-27

Abstract: Controlling the intensity of emitted light and charge current is the basis of transferring and processing information. By contrast, robust information storage and magnetic random-access memories are implemented using the spin of the carrier and the associated magnetization in ferromagnets. The missing link between the respective disciplines of photonics, electronics and spintronics is to modulate the circular polarization of the emitted light, rather than its intensity, by electrically controlled magnetization. Here we demonstrate that this missing link is established at room temperature and zero applied magnetic field in light-emitting diodes, through the transfer of angular momentum between photons, electrons and ferromagnets. With spin–orbit torque, a charge current generates also a spin current to electrically switch the magnetization. This switching determines the spin orientation of injected carriers into semiconductors, in which the transfer of angular momentum from the electron spin to photon controls the circular polarization of the emitted light. The spin–photon conversion with the nonvolatile control of magnetization opens paths to seamlessly integrate information transfer, processing and storage. Our results provide substantial advances towards electrically controlled ultrafast modulation of circular polarization and spin injection with magnetization dynamics for the next-generation information and communication technology, including space–light data transfer. The same operating principle in scaled-down structures or using two-dimensional materials will enable transformative opportunities for quantum information processing with spin-controlled single-photon sources, as well as for implementing spin-dependent time-resolved spectroscopies.

DOI: 10.1038/s41586-024-07125-5

Source: https://www.nature.com/articles/s41586-024-07125-5