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Researchers Control the Flip of Electron Spin
karvind writes "According to PhysOrg, physicists in Europe, California and at Ohio University now have found a way to manipulate the spin of an electron with a jolt of voltage from a battery. In this experiment voltage was applied to Indium Arsenide based quantum dot which flipped the spin of electron inside it and emitted a photon. The scientists were able to manipulate how long it would take for the electron to flip its spin and emit a photon - from one to 20 nanoseconds. This may have possible applications in optoelectronics and quantum cryptography. Results were published in the latest issue of Physics Review Letters"
How about an ansible?
Pair off two electrons in a shell, flip the rotation of one and you change the rotation of another - instanteously. Even if they're no longer in the same atom and millions of miles apart.
The only surefire protection against Microsoft infections is abstinence. - The Onion
I found myself reading this article quite mindful of the frequency of stories recently that suggest the US is headed down a dangerous path of neglect and ignorance. Not only in the arena of biological research (stem cell, et al) but in technological developments as well. This is not a matter of observation but rather official administrative policy http://science.slashdot.org/article.pl?sid=05/04/0 2/183230&tid=98&tid=103&tid=190&tid=215&tid=231&ti d=14 .
"The study was funded by EPSRC in the United Kingdom, Ohio University, Volkswagen, and the Alexander von Humboldt Foundations, with additional support by the Scottish Executive and the Royal Society of Edinburgh"
It seems to me that this is exactly one example of the type of technology the government should be promoting, for military benefit or not. What I am not sure of is wether the researches had the option to solicit US funding or if they chose rather to not bother?
I don't know, it struck me as a little odd considering that we're told repeatedly about how important it is to be a world leader in economy, technology, and security here is something that promotes all three and the pentagon's fat couffers are nowhere to be found. (well potentially compromises the third, but that's another story)
The List of Grievances with Slashdot.
Quantum error correction can be used to fix quantum errors. If the errors are independent, local, then there is a fault tolerant threshold, below which you will be able to correct enough errors to do arbitrary quantum computation. Error correction will typically add polylog (polynomial in log n) overhead in the number of qubits and the running time. So Shor's factoring algorithm becomes O(n^3 log^a n) instead of O(n^3).
No, it doesn't need to be completely sheilded. As far as 'reading' the information simultaneously detroying the quantum state, that is true...just like reading a memory cell that uses a capacitor destroys the information, yet we miraculously still build computers with them :P. Also, the application of quantum computers is quite limited (factoring numbers is one thing they can do well), don't expect to be playing Doom 6 on them.
And don't think of that 'other world' explanation. It's not really what is happening according to current theory, just a convenient/spooky way to explain it to some lay people. And yes, IAAP