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Gina Miller writes "An article on the Physics News Update website Nanospintronics: A Single-Spin Transistor reports on the Institute for Microstructural Sciences that is responsible for the first prototype. "The spins of the electrons in the transistor are not random but depend on the number of electrons in the electron puddle, and on the applied magnetic field. Most importantly, by connecting the dot to spin-polarized reservoirs, one can insist that the electrons flowing in or out have their spins aligned up or down, and this criterion (is the electron's spin up or down?) can be used as a gate to allow a high or low current to flow through the dot." This new spin polarized phase technique could be used in quantum computing."

3 Responses to “Nanospintronics”

  1. The Living Fractal Says:


    ok I finally got this post through the lameness (or should I same lame) filter. It claims I am yelling… and I use maybe 3 acronyms…'s stupid… on to my thoughts on the article. This is all great news, and I'm extremely happy to see progress, but I still wonder… I mean, ok, you build the pieces for a quantum bit and then you put them together very carefully and you get what? This spintronics stuff sounds wonderful, but how do you put it all together? I know qubits are supposedly superpositionable (lol is that a word?), but how in the heck do you program a qubit-version of MS Windows xp Pro? I mean, what!? Would a quantum computer operate under even remotely the same architecture as a pc today? Could you simply upgrade the cpu in today's pc's with a "qpu" or whatever? I'm just trying to see how this will get to my desk. And not in ten years, I want it yesterday.

  2. Mr_Farlops Says:


    And it's possible that nothing will come of it.

    Remember all the hype about josephson junctions back in the early Eighties? Remember how gallium arsenide chips were going to revolutionize the industry? Photonics has also been "just around the corner" for twenty years now.

    Then again quantum computers are supposed to be qualitatively different from classical computers so, who knows? I guess we'll all just have to wait and see if anyone actually makes commercial devices out of all this stuff.

  3. waynerad Says:


    Hi. I think there is a bit of misunderstanding here. You would not use quantum computing hardware to run MS Windows. Quantum computing is only useful for solving what are known in mathematics as "NP Hard" problems. NP Hard problems are "intractable" for a classical computer — "intractable" means that you can't solve it without waiting millions of years. For example, you might use a quantum computer for computing Peter Shor's algorithm for factoring numbers. If you tried to do this calculation on your Windows XP desktop, it would take "forever". The ability to solve these types of problems could, concievably, greatly accelerate scientific and technological progress, even the machines are used only in high-tech manufacturing or science research labs and never touch your desktop. See Matthew Hayward's website on this topic, "Quantum Computing and Shor's Algorithm" for more information.

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