Author(s): Wei, YM (Wei, Yuming); Liu, SF (Liu, Shunfa); Li, XS (Li, Xueshi); Yu, Y (Yu, Ying); Su, XB (Su, Xiangbin); Li, SL (Li, Shulun); Shang, XJ (Shang, Xiangjun); Liu, HQ (Liu, Hanqing); Hao, HM (Hao, Huiming); Ni, HQ (Ni, Haiqiao); Yu, SY (Yu, Siyuan); Niu, ZC (Niu, Zhichuan); Iles-Smith, J (Iles-Smith, Jake); Liu, J (Liu, Jin); Wang, XH (Wang, Xuehua)

Source: NATURE NANOTECHNOLOGY DOI: 10.1038/s41565-022-01092-6 Early Access Date: APR 2022

Abstract: Deterministic single-photon sources are a key building block for photonic quantum technologies. Stimulated emission now helps tailoring spontaneous emission from a ladder-type three-level system in a single epitaxial quantum dot for bright polarized sources with a high photon purity and indistinguishability.

The coherent interaction of electromagnetic fields with solid-state two-level systems can yield deterministic quantum light sources for photonic quantum technologies. To date, the performance of semiconductor single-photon sources based on three-level systems is limited mainly due to a lack of high photon indistinguishability. Here we tailor the cavity-enhanced spontaneous emission from a ladder-type three-level system in a single epitaxial quantum dot through stimulated emission. After populating the biexciton (XX) of the quantum dot through two-photon resonant excitation, we use another laser pulse to selectively depopulate the XX state into an exciton (X) state with a predefined polarization. The stimulated XX-X emission modifies the X decay dynamics and improves the characteristics of a polarized single-photon source, such as a source brightness of 0.030(2), a single-photon purity of 0.998(1) and an indistinguishability of 0.926(4). Our method can be readily applied to existing quantum dot single-photon sources and expands the capabilities of three-level systems for advanced quantum photonic functionalities.

Accession Number: WOS:000780825800001

PubMed ID: 35410369

ISSN: 1748-3387

eISSN: 1748-3395

Full Text: https://www.nature.com/articles/s41565-022-01092-6