Room temperature superradiance due to coherent coupling between light and extended single quantum state
Room temperature superradiance due to coherent coupling between light and extended single quantum state
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由于光与扩展单量子态之间的相干耦合而产生的室温超辐射
DOI：
10.1016/j.jnoncrysol.2012.02.019
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发表时间：
2012
影响因子：
3.5
通讯作者：
H. Ishihara and T. Itoh
中科院分区：
文献类型：
--
作者：
M. Ichimiya;H. Yasuda;M. Ashida;H. Ishihara and T. Itoh
建立了一种新的基于分子束外延的高质量CuCl薄膜生长方法。在合格的膜中，其中在多个波长的范围内实现激子极化波和共振电磁波之间的协调耦合，我们已经观察到激子在室温下的异常高速的非线性响应，其中激子在其相干性被退相破坏之前辐射衰减。只有当其他辐射宽度较小的组分因室温退相而消失时，才能在非线性光谱中观察到具有极大辐射宽度的组分。最大辐射宽度的激子态的辐射衰减时间达到100 fs量级，比退相过程快得多。我们的研究结果表明的机制与传统的基于长波长近似的光-物质相互作用的物理描述相矛盾。测量的简并四波混频谱和辐射衰减曲线的形状分别与计算的诱导偏振谱和实时分析得到的辐射衰减曲线的形状相吻合。
We have established the newly-developed growth method of high-quality CuCl thin film based on molecular-beam epitaxy. In qualified films, where harmonized coupling between an excitonic polarization wave and a resonant electromagnetic wave over a range of multiple wavelengths is achieved, we have observed an exceptionally high speed nonlinear response of excitons at room temperature, wherein the excitons decay radiatively before its coherence is destroyed by dephasing. A component with extremely large radiative width can be observed in the nonlinear optical spectrum only when the other components with smaller radiative widths disappear by the room-temperature dephasing. The radiative decay time of the excitonic state with the largest radiative width reaches the order of 100fs, which is much faster than the dephasing process. The mechanism demonstrated by our results contradicts the conventional physical description of light–matter interaction based on the long-wavelength approximation. The shapes of the measured degenerate four-wave mixing spectrum and the radiative decay profile closely reflect those of the calculated induced-polarization spectrum and the radiative decay profile obtained by real-time analysis, respectively.