Reliable quantum-bit production could ease the way to high-speed computers.

UK physicists have made a key step towards practical quantum computing: they have created a light source that fires entangled photons when triggered by an electric current. Quantum computers exploit the inherent uncertainties of quantum physics to perform calculations much faster than computers currently in use. Whereas conventional 'bits' of information take only the values zero or one, quantum bits, or 'qubits', exist in a fuzzy superposition of both.   

[Source: nature.com; photo D. Brunner/iStockphoto]

Putting a quantum dot together with an LED can produce entangled photons on demand