希腊克里特大学Savvidis, Pavlos G.团队近日揭示了各向异性二维钙钛矿微腔中的不对称拓扑光子态。该研究于2025年5月29日发表在《光：科学与应用》杂志上。

各向异性微腔中的光子Rashba-Dresselhaus耦合为实现具有非零Berry曲率的非传统拓扑态提供了一个引人注目的平台。研究组探索了一种由限制在微腔内的各向异性取向的有机/无机卤化物钙钛矿层组成的自组装二维杂化结构。这些钙钛矿系统的强光学各向异性，由显著的折射率对比和室温下的强激子共振驱动，使得能够产生介导光子和极化相互作用的合成磁场。 

偏振依赖模式和空间反转对称破缺之间的相互作用导致了强烈的光子Rashba-Dresselhaus自旋轨道耦合，从而导致能带拓扑和能量色散的明显变化。这些效应导致在室温下在光子带和极化带内形成非常规拓扑特征，包括非零Berry曲率和离轴恶魔点。

该发现揭示了光学和几何各向异性在光的工程合成规范场中的关键作用，为设计具有新颖拓扑特性的光子系统提供了一种通用的方法。通过利用卤化物钙钛矿的独特性质及其支持室温激子和大双折射的能力，这项工作推动了用于拓扑光子学和旋量光子学应用的极化平台的发展。

附：英文原文

Title: Unveiling asymmetric topological photonic states in anisotropic 2D perovskite microcavities

Author: Mavrotsoupakis, Emmanouil G., Mouchliadis, Leonidas, Cao, Junhui, Chairetis, Minoas C., Triantafyllou-Rundell, Marios E., Macropulos, Eleni C. P., Paschos, Giannis G., Pantousas, Apostolos, Liu, Huaying, Kavokin, Alexey V., Ohadi, Hamid, Stoumpos, Constantinos C., Savvidis, Pavlos G.

Issue&Volume: 2025-05-29

Abstract: Photonic Rashba-Dresselhaus coupling in anisotropic microcavities offers a compelling platform for realizing unconventional topological states with non-zero Berry curvature. In this study, we explore a self-assembled two-dimensional hybrid structure composed of anisotropically oriented organic/inorganic halide perovskite layers confined within a microcavity. The strong optical anisotropies of these perovskite systems, driven by significant refractive index contrasts and robust excitonic resonances at room temperature, enable the emergence of synthetic magnetic fields that mediate photonic and polaritonic interactions. The interplay between polarization-dependent modes and spatial inversion symmetry breaking gives rise to strong photonic Rashba-Dresselhaus spin-orbit coupling, leading to distinct modifications in band topology and energy dispersions. These effects result in the formation of unconventional topological features, including non-zero Berry curvature and off-axis diabolical points, within the photonic and polaritonic bands at room temperature. Our findings reveal the critical role of optical and geometric anisotropies in engineering synthetic gauge fields for light, providing a versatile approach for designing photonic systems with novel topological properties. By leveraging the unique properties of halide perovskites and their ability to support both room-temperature excitons and large birefringence, this work advances the development of polaritonic platforms for applications in topological photonics and spinoptronics.

DOI: 10.1038/s41377-025-01852-8

Source: https://www.nature.com/articles/s41377-025-01852-8