A metallic quantum dot sandwiched between two superconductors – which functions as an electronic turnstile, only permitting one electron through at a time – has been developed by researchers in France, Russia and Finland. By driving an AC voltage through the device, the researchers can control the tunnelling of electrons into and out of the dot. While such turnstiles have been made before, this is the first where electrons at only one quantum energy level are allowed to pass through. This, say the researchers, makes the device ideal for quantum-metrology applications……
http://nanotechweb.org/cws/article/tech/64955
