1. Telecom wavelength single-photon source based on InGaSb/AlGaSb quantum dot technology
- Author
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Hakkarainen, Teemu, Hilska, Joonas, Hietalahti, Arttu, Ranta, Sanna, Peil, Markus, Kantola, Emmi, Chellu, Abhiroop, Sen, Efsane, Penttinen, Jussi-Pekka, and Guina, Mircea
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
Deterministic light sources capable of generating quantum states on-demand at wavelengths compatible with fiber optics and atmospheric transmission are essential for practical applications in quantum communication, photonic quantum computing, and quantum metrology. To this end, single-photon emission at 1500 nm is demonstrated from an InGaSb quantum dot (QD) grown by filling droplet-etched nanoholes for the first time. The QD was embedded in a device structure comprising an antimony-based high refractive index contrast back-reflector designed for cryogenic operation and a solid immersion lens for improved photon extraction. The longitudinal optical (LO) phonon assisted excitation of the QD ground state and quasi-resonant excitation of the QD excited state is realized with a novel compact wavelength-tunable power-stabilized semiconductor laser. These direct approaches to exciting a single QD unlock access to its excitonic fine structure. The neutral exciton-biexciton structure exhibits a negative binding energy of 1.4 meV (2.6 nm) and a fine structure splitting of 24.1+/-0.4 ueV. Furthermore, spectrally pure/isolated emission from a charged single exciton state with a single-photon purity of 95 % is achieved with LO phonon assisted two-color excitation. These results represent a major step forward for the use of the novel antimonide-based QD emitters as deterministic quantum light sources in complex quantum secure networks exploiting the wavelength compatibility with standard telecom fibers., Comment: 12 pages, 4 figures, supplementary information
- Published
- 2024