Physicists from the National Institute of Standards and Technology (NIST) and their colleagues have achieved a major new feat — creating a bizarre “quantum” interference between two photons of markedly different colors, originating from different buildings on the University of Maryland campus.
The experiment is an important step for future quantum communications and quantum computing. The interference between two photons could connect distant quantum processors, enabling an internet-like quantum computer network.
Using photons that originally had different wavelengths is important because it mimics the way a quantum computer would operate. For instance, visible-light photons can interact with trapped atoms, ions or other systems that serve as quantum versions of computer memory while longer-wavelength (near-infrared) photons are able to propagate over long distances through optical fibers. (Science Daily)