Free Republic

Government Lab Reveals It Has Operated Quantum Internet for Over Two Years A quantum internet capable of sending perfectly secure messages has been running at Los Alamos National Labs for the last two and a half years, say researchers One of the dreams for security experts is the creation of a quantum internet that allows perfectly secure communication based on the powerful laws of quantum mechanics.The basic idea here is that the act of measuring a quantum object, such as a photon, always changes it. So any attempt to eavesdrop on a quantum message cannot fail to leave telltale signs...

Researchers at the Max Planck Institute of Quantum Optics (MPQ) in Garching, Germany have achieved unprecedented control over the creation of single photons (Nature, October 28, 2004). By using a tightly trapped single calcium ion, localized between two ultra-high reflectivity mirrors, and subjecting it to an external laser pulse, the scientists could emit photons one by one. The emission time and the pulse shape of each photon were completely user-controlled. Remarkably, the device was operated without interruption over a period limited only by the trapping time of the ion, typically many hours. The achievement has important applications in quantum information...