Double-Pulse Generation of Indistinguishable Single Photons with Optically Controlled Polarization

• DOI: 10.1021/acs.nanolett.1c03543
• Publication Date: 2022-02-11T19:49:26Z
• Authors: Junyong Yan; Shunfa Liu; Xing Lin; Yongzheng Ye; Jiawang Yu; Lingfang Wang; Ying Yu; Yanhui Zhao; Yun Meng; Xiaolong Hu; Da-Wei Wang; Chaoyuan Jin; Feng Liu
• Keywords: Biexciton

Single-photon sources play a key role in photonic quantum technologies. Semiconductor dots can emit indistinguishable single photons under resonant excitation. However, the resonance fluorescence technique typically requires cross-polarization filtering, which causes loss of unpolarized dot emission by 50%. To solve this problem, we demonstrate method for generating with optically controlled polarization two laser pulses off-resonant neutral exciton states. This scheme is realized exciting to biexciton state and subsequently driving an eigenstate. By combining magnetic field, demonstrated generation (the degree 101(2)%), laser-neutral detuning up 0.81 meV, high single-photon purity (99.6(1)%), indistinguishability (85(4)%). Laser be blocked using spectral filtering. Our work makes important step toward near-unity collection efficiency.