Quantum Optics with Self-Assembled Quantum Dots

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 [2]. 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 [3] and the indistinguishability of the emitted photons is extracted [4] and the fundamental limits exploited [5]. Furthermore, various out-coupling strategies for efficiently transferring single photons to an optical fiber are implemented [6]. The unique engineering potential of the nanophotonic waveguides is demonstrated by implementing a chiral quantum interface [7,8]. The prospects and applications of single-photon nonlinearities [9,10] and architectures for scalable quantum networks are discussed [11].

[1] Lodahl et al., Rev. Mod. Phys. 87, 347 (2015).
[2] Lodahl, Quantum Science and Technology 3, 013001 (2018).
[3] Arcari et al., Phys. Rev. Lett. 113, 093603 (2014).
[4] Kirsanske et al., Phys. Rev. B 96, 165306 (2017).
[5] Tighineanu et al., submitted, ArXiv: 1702.04812 (2017).
[6] Daveau et al., Optica 4, 178 (2017).
[7] Söllner et al., Nature Nano. 10, 775 (2015).
[8] Lodahl et al., Nature 541, 473 (2017).
[9] Javadi et al., Nature Comm. 6, 8655 (2015).
[10] Ralph et al., Phys. Rev. Lett. 114, 173603 (2015).
[11] Mahmoodian et al., Phys. Rev. Lett. 117, 24501 (2016)

Bio: Peter Lodahl is professor in quantum physics at the Niels Bohr Institute, University of Copenhagen and leads the Quantum Photonics Group. His research focus on solid-state quantum optics and quantum-information processing with quantum dots. He is the recipient of an ERC consolidator grant (2010), an ERC advanced grant (2015), and the EliteForsk Award for 2016. He is Director of the Danish National Research Foundation Center of Excellence for Hybrid Quantum Networks (Hy-Q) and Scientific Director of the Danish Quantum Innovation Center Qubiz. He is an elected member of the Royal Danish Academy of Sciences and Letters (2016).