Producing High Quality Photons for Quantum Networks
The computer I am writing this news item on is connected to the Internet using an Ethernet cable, which transmits information as an electrical signal, but that information has not been transmitted exclusively like that. Somewhere along the line fiber optics were used because of how quickly and efficiently optical signals transmit data, but currently they are only used as analogs for the electrical signal. In the future though, photons will be used quite differently to create a quantum Internet, and researchers at the University of Cambridge have recently accomplished something to bring that future closer to the present.
Among the challenges for creating a quantum Internet is the ability to generate single photons with special properties. Researchers have already looked at using quantum dots for this, but typically the photons are of a low quality that is unsuited for a quantum mechanical system. The Cambridge researchers however have found a way to generate higher quality photons by utilizing weak excitation of the quantum dots. This changes the mechanism for producing the photons to one that will generate photons more like what you would expect from a laser.
Though the researchers used quantum dots for this work, but its results can be applied to other single-photon sources, such as nanowires. Potentially this method could be applied to future quantum technologies besides quantum networking that also rely on quantum entanglement and teleportation.
Source: University of Cambridge