Strain-tunable entangled-light-emitting diodes with high yield and fast operation speed

摘要

Triggered sources of entangled photons play crucial roles in almost anyexisting protocol of quantum information science. The possibility to generatethese non-classical states of light with high speed and using electrical pulsescould revolutionize the field. Entangled-light-emitting-diodes (ELEDs) based onsemiconductor quantum dots (QDs) are at present the only devices that canaddress this task 5. However, ELEDs are plagued by a source of randomness thathampers their practical exploitation in the foreseen applications: the very lowprobability (~10-2) of finding QDs with sufficiently smallfine-structure-splitting for entangled-photon-generation. Here, we overcomethis hurdle by introducing the first strain-tunable ELEDs (S-ELEDs) thatexploit piezoelectric-induced strains to tune QDs forentangled-photon-generation. We demonstrate that up to 30% of the QDs inS-ELEDs emit polarization-entangled photon pairs with entanglement-fidelitiesas high as f+ = 0.83(5). Driven at the highest operation speed of 400 MHz everreported so far, S-ELEDs emerge as unique devices for high-data rateentangled-photon applications.