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Supercomputing Hardware Science

Physicists Improve Spin Information Storage 43

schliz writes "Researchers have made headway into developing spintronic RAM by successfully transferring spin information from an electron to a more robust atomic nucleus and accessing the information 2,000 times in 100 seconds before it decayed (abstract). The demonstration was conducted using phosphorus-doped silicon in a highly magnetized, low-temperature environment (8.59 Tesla, -269.5 degrees Celsius). Other researchers have achieved spin lifetimes of 30 hours in a weaker magnetic field (0.3 Tesla)."
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Physicists Improve Spin Information Storage

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  • by SgtKeeling ( 717065 ) on Friday December 17, 2010 @12:21PM (#34589408) Journal

    -269.5 degrees Celsius

    This seems to me like a very appropriate time to use Kelvin. For anyone interested, this is 3.65 degrees Kelvin.

    • And 8.5 Teslas is approximately 2 to 3 times the magnetic field strength of a typical MRI machine, so this technology isn't quite ready for cell phones yet.
      • Pff, if they put it in cell phones I’m sure it would be safe.

      • Approximately 2 to 3 times the magnetic field strength of a typical MRI

        You just need one of those Cellphone Head Protectors, and at $30 it's a real bargain. "Between 20% and 80% of the radiation emitted by a mobile phone is deposited in the user's head. The microwave radiation is absorbed by and actually penetrates the area around the head, some reaching an inch, to an inch and a half, into the brain. Protect yourself by ordering our radiation protector."

        Or just use speakerphone like I do, so you don't have to hold the phone to ya head and kill brain cells. (drinks 30th be

    • They're just Kelvin, not "degrees Kelvin".
    • Now you're on the subject of units, why isn't the decay time measure in whatmeworrys?
  • Physicists Improve Spin Information Storage

    Does that mean we'll be able to fit Rush's broadcasts from 2001 to 2009 on a floppy?

    • by Anonymous Coward

      The information content of Rush's broadcasts is very low, therefore it should be highly compressible... thus should already fit on a floppy.

  • ... environment (8.59 Tesla, -
    269.5 degrees Celsius)...

    Poor choice of Line Feed location. I didn't see the negative before. 269.5 C didn't seem that bad.

  • I thought we have long established that science and politics do not mix well. And now they are creating spin technologies? Is it really an improvement or is it, in itself just more spin?

  • highly magnetized, low-temperature environment (8.59 Tesla, -269.5 degrees Celsius).

    Well, that pretty well sums up the weather forecast for here tomorrow . . .

    • highly magnetized, low-temperature environment (8.59 Tesla, -269.5 degrees Celsius).

      Well, that pretty well sums up the weather forecast for here tomorrow . . .

      +1 lives on gigantic electromagnet

    • by mcgrew ( 92797 ) *

      That's still not as cold as my ex-wife's heart, though.

  • I'm not a physicist, so someone please answer my (stupid?) question. Why is that ground-breaking technologies ranging from quantum computing, super conductivity, to now this requires insane levels of cold? Is it because this is pure theoretical research, and that practical materiel science and engineering comes later?

    • Building a really big electromagnet requires superconducting materials because of the immense amount of current required to generate the electric field. If the material wasn’t a superconductor, the resistance would generate so much heat that it would burn up.

      • Also (replying to myself, sorry), for what it’s worth, if you think that’s “insanely cold” you’re looking at it from exactly the wrong perspective. Cold is just the absence of heat. It just has very, very little heat. Almost none, in fact... 0 degrees C, by contrast, could be called “insanely hot”.

        Heat causes noise and interference. Plenty of examples exist. You know the ripples you see coming off pavement? Heat. Electronics generally become less reliable the hotter

      • by Laukei ( 1099765 )
        There is that, but equally for applications that require no magnetic field, things that are hot have lots of energy. Energetic particles bouncing around everywhere couple to your meticulously-set-up experiment to the environment, destroying your isolated system [] and removing the quantum effects you're utilizing.

        For quantum computing, one of the requirements specified by the di Vincenzo criteria [] are long decoherence times. Heat seriously reduces those.
    • Re: (Score:3, Informative)

      by Anonymous Coward

      Subatomic things tend to move around when they get warm. Cooling them keeps them where they're put, it's easier to find them that way.

      • Subatomic things tend to move around when they get warm.

        The amount that subatomic things more around is the definition of warmth.

        • > The amount that subatomic things move around is the definition of warmth.

          No. The amount that atomic things move around is the definition of warmth.

    • by grimJester ( 890090 ) on Friday December 17, 2010 @01:07PM (#34589980)
      At least some of those are because quantum decoherence [] happens faster when temperature rises. The time before quantum behavior turns into normal classical behavior is inversely proportional to temperature in Kelvin. (I tried to find something sane on Wikipedia, but all relevant articles seem to be written for experts...)

      A more general explanation could be that new stuff happens at very low energies and very high energies compared to what we're used to. Cold is just low energy.
    • by blueg3 ( 192743 )

      Subtle or tricky quantum-mechanical effects are washed out or destroyed at higher temperatures (all of the atom's kinetic energy that is what we measure as temperature). So anything new and quantum mechanical is likely to be done near absolute zero, since that's the easiest environment to work in.

    • Roughly for the same reason why macroscopic technologies tend to work less well during an earthquake.

    • by Zinho ( 17895 )

      Regarding electron spins, there's a really good reason for the insane levels of cold - electron spin transitions require incredibly small energies. Some quick wiki-ing [] leads me to a value of 159.3*10^-24 joules to change spin at the magnetic field strengths cited in the summary. If I had to take a guess, the researchers are trying to keep the kinetic energy of the atoms being tested below that energy threshold so that the spin doesn't change randomly with Brownian motion.

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