Quantiki

Quantum Information Theory is the study of information-processing tasks such as storage and transmission of information, or manipulation of entanglement, using quantum-mechanical systems. Until very recently, the study of these processes was limited to the case in which the required resources, e.g. information sources, communication channels or entanglement resources, were assumed to be available for an infinite number of independent uses. In reality, however, resources are used a finite number of times, and there are unavoidable correlations between their successive uses.

QD Vision, based in Watertown, MA, is promoting a new LED-based lamp that it made with Nexxus Lighting of Charlotte, NC. Nexxus makes a lamp designed to screw into standard sockets used in recessed ceiling lighting. It consists of an array of white-light LEDs encircled by fins that remove excess heat. QD Vision adds an optic--a plastic cover with a special coating that snaps into place over the LEDs. It's that coating that makes the difference in the quality of the light. It consists of quantum dots--tiny bits of semiconductor material just a few nanometers in diameter.

A team of physicists from Austria has sent pairs of entangled photons, which can be used to encrypt messages with complete security, between telescopes spaced 144km apart in the Canary Islands. The researchers say that preserving entanglement over this distance shows the feasibility of carrying out quantum cryptography using a worldwide network of satellites.