论文标题
在二维半导体磁铁$ \ mathrm {cri_3} $中观察激子的极性特征
Observation of the polaronic character of excitons in a two-dimensional semiconducting magnet $\mathrm{CrI_3}$
论文作者
论文摘要
激子动力学可以通过电子音波耦合受到晶格振动的强烈影响。这很少在二维磁性半导体中探索。以双层CRI3为重点，我们首先通过温度依赖性的光致发光和吸收光谱表明存在强电子偶联。然后，我们报告了对拉曼光谱中第8阶的周期性广泛模式的观察，这归因于激子的二极分子特征。我们确定这种二极管特性由1.96 eV的电荷转移激子与120.6 cm-1的纵向光学声子之间的耦合主导。我们进一步表明，远程磁顺序的出现使电子 - 音波耦合强度提高了约50美元$ \％$，并且从分层的抗fiferromagnetic到铁磁秩序的过渡会导致周期性广泛模式的光谱强度，这表明在lattice，Chartice offer office cri和dimensential cri 3中均具有强大的耦合。我们的研究为在二维磁性半导体中定制光结物相互作用开辟了机会。
Exciton dynamics can be strongly affected by lattice vibrations through electron-phonon coupling. This is rarely explored in two-dimensional magnetic semiconductors. Focusing on bilayer CrI3, we first show the presence of strong electron-phonon coupling through temperature-dependent photoluminescence and absorption spectroscopy. We then report the observation of periodic broad modes up to the 8th order in Raman spectra, attributed to the polaronic character of excitons. We establish that this polaronic character is dominated by the coupling between the charge-transfer exciton at 1.96 eV and a longitudinal optical phonon at 120.6 cm-1. We further show that the emergence of long-range magnetic order enhances the electron-phonon coupling strength by about 50$\%$ and that the transition from layered antiferromagnetic to ferromagnetic order tunes the spectral intensity of the periodic broad modes, suggesting a strong coupling among the lattice, charge and spin in two-dimensional CrI3. Our study opens opportunities for tailoring light-matter interactions in two-dimensional magnetic semiconductors.
