Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Materials Science and Engineering, Hunan University, Changsha, Hunan 410082, P. R. China.
Science. 2020 Oct 30;370(6516):600-604. doi: 10.1126/science.abc4975. Epub 2020 Oct 8.
Topological photonics in strongly coupled light-matter systems offer the possibility for fabricating tunable optical devices that are robust against disorder and defects. Topological polaritons, i.e., hybrid exciton-photon quasiparticles, have been proposed to demonstrate scatter-free chiral propagation, but their experimental realization to date has been at deep cryogenic temperatures and under strong magnetic fields. We demonstrate helical topological polaritons up to 200 kelvin without external magnetic field in monolayer WS excitons coupled to a nontrivial photonic crystal protected by pseudo time-reversal symmetry. The helical nature of the topological polaritons, where polaritons with opposite helicities are transported to opposite directions, is verified. Topological helical polaritons provide a platform for developing robust and tunable polaritonic spintronic devices for classical and quantum information-processing applications.
强耦合光物质体系中的拓扑光子学为制造对无序和缺陷具有鲁棒性的可调谐光学器件提供了可能。拓扑极化激元，即杂化激子-光子准粒子，已被提议用于展示无散射的手性传播，但迄今为止，它们的实验实现是在深低温和强磁场下进行的。我们在没有外加磁场的情况下，在单层 WS 激子中演示了螺旋拓扑极化激元，该激子与由赝时间反转对称性保护的非平凡光子晶体耦合。拓扑极化激元的螺旋性质得到了验证，其中具有相反螺旋的极化激元被输送到相反的方向。拓扑螺旋极化激元为开发用于经典和量子信息处理应用的稳健可调谐极化激子自旋电子器件提供了平台。
