Optics and photonics
A small device churns out pairs of entangled photons with the help of an unusual material.
A device uses an unconventional material to produce ‘entangled’ photons, a valued commodity for quantum technologies, more than 1,000 times faster than a competing approach.
Two photons in an entangled pair have tightly linked properties and can be used for a range of applications, including secure quantum communications. To generate entangled photon pairs, researchers have begun developing compact chips as an alternative to older set-ups that occupy entire laboratory benches. One promising approach uses chip components made of silicon on an electrically insulating layer.
Galan Moody at the University of California, Santa Barbara, and his colleagues instead used a mixture of aluminium, gallium and arsenic, building micrometre-scale rings from the material on top of an insulator. When the researchers fed laser light into such a ring, they generated entangled photon pairs at more than 1,000 times the rate of sources built from silicon on an insulator.
The team says this combination could be used to create compact ‘quantum photonic’ chips that include a variety of components, such as structures to carry photons much as wires carry electrons. Such chips could be used for information processing and satellite communications.