SEMICONDUCTING nanowires could one day store and process data in quantum computers.
A team of researchers led by Silvano De Franceschi of the Delft University of Technology in the Netherlands made nanowires out of indium arsenide, each about 100 nanometres in diameter and 100 times as long. By attaching aluminium electrodes to the ends of the wires, they could probe the wires鈥� behaviour at temperatures close to absolute zero. At such temperatures aluminium becomes superconducting, able to conduct electrical current with zero resistance.
The team found that the superconducting electrodes induced similar behaviour in the nanowires because the superconducting properties leaked into the wire 鈥� the so called 鈥減roximity effect鈥�. By applying a voltage to the substrate on which the nanowires rested they could alter the strength of the proximity effect and so turn the superconductivity on and off at will (Science, vol 309, p 272).
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Because superconductivity is an inherently quantum effect, superconducting nanowires could form part of the quantum circuitry necessary for a future quantum computer. They could store information, or help read out the result of a calculation.
