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arXiv · 1905.00275

Coherently driving a single quantum two-level system with dichromatic laser pulses

Yu-Ming He·Hui Wang·Can Wang·Ming-Cheng Chen·Xing Ding·Jian Qin·Zhao-Chen Duan·Si Chen·Jin-Peng Li·Run-Ze Liu·Christian Schneider·Mete Atature·Sven Hoefling·Chao-Yang Lu·Jian-Wei Pan
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Abstract

Efficient excitation of a single two-level system usually requires that the driving field is at the same frequency as the atomic transition. However, the scattered laser light in solid-state implementations can dominate over the single photons, imposing an outstanding challenge to perfect single-photon sources. Here, we propose a background-free method using a phase-locked dichromatic electromagnetic field with no spectral overlap with the optical transition for a coherent control of a two-level system, and we demonstrate this method experimentally with a single quantum dot embedded in a micropillar. Single photons generated by pi excitation show a purity of 0.988(1) and indistinguishability of 0.962(6). Further, the phase-coherent nature of the two-color excitation is captured by the resonance-fluorescence intensity dependence on the relative phase between the two pulses. Our two-color excitation method adds a useful toolbox to the study of atom-photon interaction, and the generation of spectrally isolated indistinguishable single photons.

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Yu-Ming He, Hui Wang, Can Wang, Ming-Cheng Chen, Xing Ding, Jian Qin, Zhao-Chen Duan, Si Chen, Jin-Peng Li, Run-Ze Liu, Christian Schneider, Mete Atature, Sven Hoefling, Chao-Yang Lu, Jian-Wei Pan. 2019-05-01. Coherently driving a single quantum two-level system with dichromatic laser pulses. https://doi.org/10.1038/s41567-019-0585-6

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