法国索邦大学Mathieu Mivelle团队研究了磁光物质相互作用的近场控制。相关论文发表在2025年3月19日出版的《光：科学与应用》杂志上。

光与物质的相互作用通常被认为主要受电场的影响，而光的磁性成分往往被忽视。尽管如此，磁场在各种光学过程中起着关键作用，包括手性光物质相互作用、光子雪崩和禁止的光化学，突显了操纵磁过程在光学现象中的重要性。

研究组探索了在纳米尺度上控制磁光和物质相互作用的能力。特别是通过实验证明，使用等离子体纳米结构，由于该纳米天线允许的亚波长磁限制，能量从磁近场转移到纳米粒子。这种控制是通过该等离子体纳米结构的特殊设计实现的，该结构经过优化，可以在空间上解耦局部等离子体场的电和磁分量。

此外，通过研究掺杂镧系离子的纳米粒子的自发辐射，研究组观察到测量的场分布与实验估计的该天线的电和磁局域态密度在空间上并不相关，这与互易性的预期相矛盾。他们证明，这种违反直觉的观察实际上是离子激发和发射所遵循的不同光路的结果，这禁止了互易定理的直接应用。

附：英文原文

Title: Nearfield control over magnetic light-matter interactions

Author: Reynier, Benot, Charron, Eric, Markovic, Obren, Gallas, Bruno, Ferrier, Alban, Bidault, Sbastien, Mivelle, Mathieu

Issue&Volume: 2025-03-19

Abstract: Light-matter interactions are frequently perceived as predominantly influenced by the electric field, with the magnetic component of light often overlooked. Nonetheless, the magnetic field plays a pivotal role in various optical processes, including chiral light-matter interactions, photon-avalanching, and forbidden photochemistry, underscoring the significance of manipulating magnetic processes in optical phenomena. Here, we explore the ability to control the magnetic light and matter interactions at the nanoscale. In particular, we demonstrate experimentally, using a plasmonic nanostructure, the transfer of energy from the magnetic nearfield to a nanoparticle, thanks to the subwavelength magnetic confinement allowed by our nano-antenna. This control is made possible by the particular design of our plasmonic nanostructure, which has been optimized to spatially decouple the electric and magnetic components of localized plasmonic fields. Furthermore, by studying the spontaneous emission from the Lanthanide-ions doped nanoparticle, we observe that the measured field distributions are not spatially correlated with the experimentally estimated electric and magnetic local densities of states of this antenna, in contradiction with what would be expected from reciprocity. We demonstrate that this counter-intuitive observation is, in fact, the result of the different optical paths followed by the excitation and emission of the ions, which forbids a direct application of the reciprocity theorem.

DOI: 10.1038/s41377-025-01807-z

Source: https://www.nature.com/articles/s41377-025-01807-z