A quantum light emitting diode for the standard telecom window around 1550 nm

TL;DR

This paper demonstrates indium phosphide quantum dot devices emitting single and entangled photons at 1550 nm, suitable for long-distance quantum communication, operable at relatively high temperatures, and integrable with existing systems.

Contribution

It introduces a new indium phosphide-based quantum dot platform capable of electrically driven single and entangled photon emission at telecom wavelengths with high fidelity and operational temperature.

Findings

Single photon emission with multiphoton suppression down to 0.11

Entangled photons with 87% fidelity

Operation temperature up to 93 K

Abstract

For the development of long-distance quantum networks, sources of single photons and entangled photon pairs emitting in the low-loss wavelength region around 1550 nm are a crucial building block. Here we show that quantum dot devices based on indium phosphide are capable of electrically injected single photon emission in this wavelength region with multiphoton events suppressed down to 0.11$\pm$0.02. Using the biexciton cascade mechanism, they further produce entangled photons with a fidelity of 87$\pm$4%, sufficient for the application of one-way error correction protocols. The new material allows for entangled photon generation up to an operating temperature of 93 K, reaching a regime accessible by electric coolers. The quantum photon source can be directly integrated with existing long distance quantum communication and cryptography systems and provides a new material platform for developing future quantum network hardware.