Near-optimal single-photon sources in the solid state

By N. Somaschi, V. Giesz, L. D. Santis, J. C. Loredo, M. P. Almeida, G. Hornecker, S. Portalupi, T. Grange, C. Antón, J. Demory and 8 more. Nature Photonics, 2015

1,217 citations recorded by the source corpus.

The scaling of optical quantum technologies requires efficient, on-demand sources of highly indistinguishable single photons. Semiconductor quantum dots inserted into photonic structures are ultrabright single-photon sources, yet the indistinguishability is limited by charge noise. Parametric downconversion sources provide highly indistinguishable photons but are operated at very low brightness to maintain high single-photon purity. To date, no technology has provided a bright source generating near-unity indistinguishability and pure single photons. Here, we report such devices made of quantum dots in electrically controlled cavities. Application of an electrical bias on the deterministically fabricated structures is shown to strongly reduce charge noise. Under resonant excitation, an indistinguishability of 0.9956 ± 0.0045 is demonstrated with g(2)(0) = 0.0028 ± 0.0012. The photon extraction of 65% and measured brightness of 0.154 ± 0.015 make this source 20 times brighter than any source of equal quality. This new generation of sources opens the way to new levels of complexity and scalability in optical quantum technologies. A single photon with near-unity indistinguishability is generated from quantum dots in electrically controlled cavity structures. The cavity allows for efficient photon collection while application of an electrical bias cancels charge noise effects.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/161d89c00643e61060630331ebdac5a64e80dbd5

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Citations in the corpus

Photonic quantum information processing: A concise review (2019, background): “In recent years, photon-on-demand sources based on quantum dots, 146 both free-space 75,147,148 and integrated 149–151 into optical waveguides, have demonstrated a signiﬁcant increase in brightness, enabling new quantum computation experimental demonstrations.”
Semiconductor quantum dots: Technological progress and future challenges (2021, background): “Over the years, the continuous improvement of In(Ga)As/GaAs eQD materials (151, 152) has led to the suppression of g((2))(t = 0) to less than 10 (153).”
Advances in quantum cryptography (2019, neutral): “Currently, the amount of output flux of these quantum sources has been limited at ∼ 10 MHz even at near unity collection efficiency [309, 310].”
Hybrid integrated quantum photonic circuits (2020, methodology): “A qubit storage unit (6), based on either an all-photonic approach (photonic analogue of electromagnetically induced transparency, as shown in the figure) or a solid-state matter qubit with controlled capture and release times, is used to synchronize the arrival of the target qubit to the one-qubit ”
Advances in quantum imaging (2024, neutral): “Quantum light sources are becoming brighter, purer and involve more photons or higher squeezing levels 90 .”