Optical trapping of single quantum dots for cavity quantum electrodynamics
We report here a nanostructure that traps single quantum dots for studying strong cavity-emitter coupling. The nanostructure is designed with two elliptical holes in a thin silver patch and a slot that connects the holes. This structure has two functionalities: (1) tweezers for optical trapping; (2) a plasmonic resonant cavity for quantum electrodynamics. The electromagnetic response of the cavity is calculated by finite-difference time-domain (FDTD) simulations, and the optical force is characterized based on the Maxwell’s stress tensor method. To be tweezers, this structure tends to trap quantum dots at the edges of its tips where light is significantly confined. To be a plasmonic cavity, its plasmonic resonant mode interacts strongly with the trapped quantum dots due to the enhanced electric field. Rabi splitting and anti-crossing phenomena are observed in the calculated scattering spectra, demonstrating that a strong-coupling regime has been achieved. The method present here provides a robust way to position a single quantum dot in a nanocavity for investigating cavity quantum electrodynamics.
基金项目：National Key R&D Program of China (2016YFA0301300).
Gang Song：School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, Chinae-mail: email@example.com
Li Yu：School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China
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Pengfei Zhang, Gang Song, and Li Yu, "Optical trapping of single quantum dots for cavity quantum electrodynamics," Photonics Research 6(3), 182-185 (2018)