Single-Photon Quantum Technology with Quantum Dots


Single-Photon Quantum Technology with Quantum Dots

Wed, 15/03/2017 -
14:30 to 15:30


Peter Lohdal
Niels Bohr Institute, University of Copenhagen, Denmark

Semiconductor quantum dots have improved their optical performance dramatically in recent years, and today a clear pathway is laid out for constructing a deterministic and coherent photon-emitter interface by embedding quantum dots in photonic nanostructures [1]. Such an interface can be employed as an on-demand single-photon source for quantum-information applications, but more generally enables single-photon nonlinearities and deterministic quantum gates. We will review the recent experimental progress on quantum dots coupled to nanophotonic waveguides and cavities enabling unique ways of engineering light-matter interaction. A single-photon coupling efficiency exceeding 98.4% is reported [2] and the coherence of the emitted photons is extracted. Furthermore, various out-coupling strategies for efficiently transferring single photons to an optical fiber are implemented [3]. Currently, the first commercial products based on this technology are being brought to the market [4]. Finally, the unique engineering potential of the nanophotonic waveguides is demonstrated by implementing a chiral quantum interface [5,6]. The prospects and applications of single-photon nonlinearities [7,8] and architectures for scalable quantum networks are discussed [9]

[1] Lodahl et al., Rev. Mod. Phys. 87, 347 (2015). [2] Arcari et al., Phys. Rev. Lett. 113, 093603 (2014). [3] Daveau et al., Optica 4, 178 (2017). [4] Single-photon chip technology is currently commercialized by the company Sparrow Quantum A/S, [5] Söllner et al., Nature Nano. 10, 775 (2015). [6] Lodahl et al., Nature 541, 473 (2017). [7] Javadi et al., Nature Comm. 6, 8655 (2015). [8] Ralph et al., Phys. Rev. Lett. 114, 173603 (2015). [9] Mahmoodian et al., Phys. Rev. Lett. 117, 24501 (2016)