Huang Ruiqin, Yang Longbo, Yang Feng, Puttisong Yuttapoom, Hu Qingsong, Li Guixian, Hu Jingnan, Hu Zhaobo, Li Liang, Tang Jiang, Chen Weimin, Han Yibo, Luo Jiajun, Gao Feng
Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan, China.
Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, China.
Nat Commun. 2025 Aug 6;16(1):7264. doi: 10.1038/s41467-025-62704-y.
Spin polarized excitons induced by spin injection from magnetic ion to a single quantum dot, has been considered as a basic unit of quantum information transfer between spin and photon for spin-photonic applications. However, this state-of-the-art technology has only been found with limited coupling strength and weak excitonic emission. Here, we demonstrate a spin-polarized self-trapped exciton naturally formed in the zero-dimensional lattice of cesium copper iodide. Upon excitation, the conversion from Cu ion to spin-1/2 Cu ion results in an in-situ self-trapped exciton, which facilitates a local Jahn-Teller distortion and guarantees the strong spin-exciton coupling and near-unity excitonic emission efficiency. Consequently, a giant Zeeman splitting of -53 meV and an effective excitonic g-factor of -93.5 are observed from magneto-photoluminescence. More importantly, this nano-scale coupling can also be driven by an external electric field, which generates electroluminescence with a circular polarization of 44.5% at 4.2 K and 8% at 300 K. The spin-optic properties of this copper compound will stimulate the fabrication of next-generation spin-photonic devices based on self-trapped excitons.
由磁性离子向单个量子点注入自旋所诱导的自旋极化激子，已被视为用于自旋光子应用的自旋与光子之间量子信息传递的基本单元。然而，这种先进技术仅在有限的耦合强度和微弱的激子发射情况下被发现。在此，我们展示了一种在碘化铯铜的零维晶格中自然形成的自旋极化自陷激子。在激发时，从铜离子到自旋1/2铜离子的转变会产生一个原位自陷激子，这促进了局部的 Jahn-Teller 畸变，并确保了强自旋-激子耦合和近乎单位的激子发射效率。因此，从磁光致发光中观察到了 -53 meV 的巨大塞曼分裂和 -93.5 的有效激子 g 因子。更重要的是，这种纳米尺度的耦合也可以由外部电场驱动，在 4.2 K 时产生圆偏振为 44.5%、在 300 K 时为 8% 的电致发光。这种铜化合物的自旋光学特性将推动基于自陷激子的下一代自旋光子器件的制造。
