Li Huanan, Yin Shixiong, Alù Andrea
Photonics Initiative, Advanced Science Research Center, City University of New York, New York, New York 10031, USA.
School of Physics, Nankai University, Tianjin 300071, China.
Phys Rev Lett. 2022 Apr 29;128(17):173901. doi: 10.1103/PhysRevLett.128.173901.
Nonreciprocity is critically important in modern wave technologies, yet its general principles and practical implementations continue to raise intense research interest, in particular in the context of broken reciprocity based on spatiotemporal modulation. Abrupt changes in time of the electromagnetic properties of a material have also been shown to replace spatial boundaries, supporting highly unusual wave-matter interactions in so-called time metamaterials. Here, we introduce nonreciprocity for temporal boundaries, demonstrating Faraday polarization rotation in a magnetoplasma with material properties abruptly switched in time. Our findings open new opportunities for time metamaterials, yielding new avenues for nonreciprocity with broad applicability for wave engineering.
非互易性在现代波技术中至关重要，但其一般原理和实际应用仍引发强烈的研究兴趣，特别是在基于时空调制的互易性破坏的背景下。材料电磁特性随时间的突然变化也已被证明可替代空间边界，在所谓的时间超材料中支持高度异常的波与物质相互作用。在此，我们引入了时间边界的非互易性，展示了在磁等离子体中材料特性随时间突然切换时的法拉第偏振旋转。我们的发现为时间超材料开辟了新机遇，为非互易性提供了新途径，在波工程中具有广泛的适用性。
