The Origin of Antibunching in Resonance Fluorescence
Lukas Hanschke, Lucas Schweickert, Juan Camilo López Carreño, Eva Schöll, Katharina D. Zeuner, Thomas Lettner, Eduardo Zubizarreta Casalengua, Marcus Reindl, Sa… 展开作者
Lukas Hanschke, Lucas Schweickert, Juan Camilo López Carreño, Eva Schöll, Katharina D. Zeuner, Thomas Lettner, Eduardo Zubizarreta Casalengua, Marcus Reindl, Saimon Filipe Covre da Silva, Rinaldo Trotta, Jonathan J. Finley, Armando Rastelli, Elena del Valle, Fabrice P. Laussy, Val Zwiller, Kai Müller, Klaus D. Jöns
Epitaxial quantum dots have emerged as one of the best single-photon sources, not only for applications in photonic quantum technologies but also for testing fundamental properties of quantum optics. One intriguing observation in this area is the scattering of photons with subnatural linewidth from a two-level system under resonant continuous wave excitation. In particular, an open question is whether these subnatural linewidth photons exhibit simultaneously antibunching as an evidence of single-photon emission. Here, we demonstrate that this simultaneous observation of subnatural linewidth and antibunching is not possible with simple resonant excitation. First, we independently confirm single-photon character and subnatural linewidth by demonstrating antibunching in a Hanbury Brown and Twiss type setup and using high-resolution spectroscopy, respectively. However, when filtering the coherently scattered photons with filter bandwidths on the order of the homogeneous linewidth of the excited state of the two-level system, the antibunching dip vanishes in the correlation measurement. Our experimental work is consistent with recent theoretical findings, that explain antibunching from photon-interferences between the coherent scattering and a weak incoherent signal in a skewed squeezed state.
Resonance fluorescence beyond the dipole approximation of a quantum dot in a plasmonic nanostructure
量子点（QD）的介观特性打破了偶极近似（DA），为光-物质相互作用的调控提供了新的维度[M. L. Andersen等人，7，215（2011）]。在这里，我们调查的功率谱和二阶相关性质的荧光从共振驱动量子点放置在一个平面金属。结果表明，由于量子点的空间延伸和金属附近的触发表面等离子体激元的剧烈变化，荧光有一个显着的贡献，从四极矩。在DA作用下，量子点取向荧光的π旋转对称性被破坏。通过控制量子点的取向和四极矩，可以使光谱在Mollow三重态和单峰之间切换，并且可以使以二阶关联函数中的反聚束为特征的荧光从弱辐射区变为强辐射区。我们的研究结果对于利用这种独特的介观效应来开发纳米光子器件具有指导意义。
