Strain-Controlled Quantum Dot Fine Structure for Entangled Photon Generation at 1550 nm

• DOI: 10.1021/acs.nanolett.1c04024
• Publication Date: 2021-12-13T13:42:31Z
• Authors: Thomas Lettner; Samuel Gyger; Katharina D. Zeuner; Lucas Schweickert; Stephan Steinhauer; Carl Reuterskiöld...; Sandra Stroj; Armando Rastelli; Mattias Hammar; Rinaldo Trotta; Klaus D. Jöns; Val Zwiller
• Keywords: Photon entanglement; Fine structure; Spontaneous parametric down-conversion; Quantum teleportation

Entangled photon generation at 1550 nm in the telecom C-band is of critical importance as it enables realization quantum communication protocols over long distance using deployed telecommunication infrastructure. InAs epitaxial dots have recently enabled on-demand entangled photons this wavelength range. However, time-dependent state evolution, caused by fine-structure splitting, currently limits fidelity to a specific state. Here, we show suppression for micromachined piezoelectric actuators and demonstrate highly nm. At lowest setting, obtain maximum 90.0 ± 2.7% (concurrence 87.5 3.1%). The concurrence remains high also moderate (weak) temporal filtering, with values close 80% (50%), corresponding 30% (80%) collected photons, respectively. presented control opens way exploiting from fiber-based protocols.