Multi-photon experiments with solid-state single-photon sources

Solid-state emitters, such as semiconductor quantum dots, are a promising platform for single-photon sources. Recent breakthroughs in material syntheses and fabrication enabled a new generation of devices, combining high emission brightness with a near unity indistinguishable pure single-photon output.

Here we will present our work towards employing quantum dot single-photon sources to realise quantum-based technologies. We focus on devices consisting of a single quantum dot deterministically coupled to a micro-pillar cavity [1,2]. Here we demonstrate a source with an absolute brightness at the output of a single-mode fibre of 14% and purities up to 99% [1,2].

We show that photons emitted with temporal separation as high as 400ns display two-photon quantum interference [2], allowing to obtain a stream of multiple temporally independent single-photons. We finally present our preliminary results employing a quantum dot source to realise entangling circuits and qubit fusion operations and to demonstrate quantum algorithms, in particular, the Boson Sampling [3,4].

[1] Loredo, et al. Optica 3 (2016).
[2] Somaschi, N., et al. Nat. Phot. 10, 340 (2016).
[3] Loredo, J. C., et al. Phys. Rev. Lett, 118, 130503 (2017).
[4] Lenzini, F., et al. Laser and Phot. Rev., 11, 1600297 (2017).