Linked by Thom Holwerda on Mon 20th Feb 2012 22:53 UTC

"A group of researchers has fabricated a single-atom transistor by introducing one phosphorous atom into a silicon lattice. Through the use of a scanning tunnelling microscope and hydrogen-resist lithography, Martin Fuechsle et al. placed the phosphorous atom precisely between very thin silicon leads, allowing them to measure its electrical behavior. The results show clearly that we can read both the quantum transitions within the phosphorous atom and its transistor behavior. No smaller solid-state devices are possible, so systems of this type reveal the limit of Moore's law - the prediction about the miniaturization of technology - while pointing toward solid-state quantum computing devices."

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Except all of our currently used public key cryptography algorithms can be broken by a quantum computer. See https://en.wikipedia.org/wiki/Post-quantum_cryptography . It turns out that NP-complete problems seem to be only hard in the worst case and easy in the average case, so no one knows how to use them for cryptography. Grover's algorithm does allow for faster solutions to NP-complete problems, but they remain exponential.

With a sufficiently powerful quantum computer, Shor's algorithm defeats RSA in polynomial time and a generalization of it can solve the discrete logarithm problem (DSA, Diffieâ€“Hellman, ElGamal) in polynomial time.

Member since:

2010-03-11

err... Actually no. Quantum Computers are NP complete for the same problems as digital computers are. So aside from maybe being faster, quantum computers don't have any advantage.