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Spintronics May Lead to Quantum Microchips
Rashan writes "A Scientific American article which waxes poetic about the possibility of microchips which use the "spin" of an electron to perform their functions." An excellent explanation of a complex subject.
Then a strange chip would be perfectly normal!
You are not the customer.
I'm afraid it is only spin.
sig is
You'll have to take that magnet out of here, this is a 'no spin' zone.
try { do() || do_not(); } catch (JediException err) { yoda(err); }
How sensitive to electro/magnetic interference would such a chip be?
In times when my neighbor can fry all my PCs with a home-made impulse gun I'd be more interested in a light-based chip.
I believe that Maytag was the first to use
spintronics.
Watch out all you chip companies, Big Bad Maytag
will sue you all for IP violations!
(In reality though wouldn't it be nice if all computers were as dependable as washing machines?)
Service guarantees Citizenship! Questions Guarantee GITMO.... Amerika Uber Alles!
No, no, Spintronics a new Richard Simmons aerobics program entirely based on twirling...
...where the executives used the spin of "stock options" to perform their functions.
GMR heads use the spin of electrons to detect changes in the magnetic field on the surface of the discs.
Napster-to-go says "Fill and refill your compatible MP3 player", which is a lie. It's not MP3. It's WMA with DRM.
I doubt it, conszidering us tech support nerds currently aren't called transistor-medics. I doubt tech support would be fiddling around with the individual electron paths of a computer.
Job? I don't have time to get a job! Who will sit around and bitch about being broke and unemployed then?
Spintronics could mean the end of booting your computer. From the article:
More sophisticated storage technologies based on spintronics are already at an advanced stage: in the next few years, MRAM (magnetic random-access memory), a new type of computer memory, will go on the market. MRAMs would retain their state even when the power was turned off, but unlike present forms of nonvolatile memory, they would have switching rates and rewritability challenging those of conventional RAM.
Think about what this means! You will be able to turn off your MRAM computer and when you turn it back on, you won't have to boot it. The computer (its memory) would be in the state in which you left it. Think of how nice that'll be!
Of course, when Windows crashed everyday, you'd still have to boot it.
Those of you who are interested in the future of alternative computing, including quantum computing, might want to check out Caltech's Computing Beyond Silicon Summer School program. The top minds from around the world will present the latest information about quantum, molecular, and DNA computing.
I'm glad I'm not the only one that recognizes just how cool QE networking would be. However, if the corps or gov get ahold of it first, it will be a bad thing. Incredibly bad.
QE transcievers by their very nature, are untraceable. Say you and I have a dialogue via anonymous email, and we agree to exchange a transciever pair. I go to Central Park at midnight, and pull the transciever pairmate out of a trashcan... we can network now, without knowing who the other is, or where they are. Chain 20 people together like that, and warez (just one example) would be unstoppable.
So, if you are part of the gov, how do you stop this? You make sure that eash QE transciever is built in such a way, that it can't be tampered with without unentangling. Then, you build a GPS reciever into it, connected to a second QE particle. It's pairmate will be in the Federal QE Network monitoring center... they'll be able to narrow it down to within a few feet geographically. It will allow them to sniff all traffic traveling through the QEnet, and will pinpoint where it is coming from.
You're infinite bandwidth will only be useful for a (nearly) infinite amount of advertising and some overpriced pay content.
The only hope we have, is that it's somehow simple to make your own QE transciever, and that someone anonymously publishes on the web just how to make your own. Make it underground.
You make sure that eash QE transciever is built in such a way, that it can't be tampered with without unentangling.
For shame. You're a reader of slashdot
You should know by now that there's no such thing as tamper-proof technology.
Believe it or not, where there's a will, there really, actually IS a way.
Technoli
Duh.
Apparently, you have no idea how *fragile* quantum entanglement is. In any other case, you might be right, but not this one.
Hell, even with conventional technology "locks" some are good enough that only the talented can manage to "pick" them. And we are talking about a case where if the majority can't defeat it, then there is no point in defeating it.
Megnetisation is the setting spin. In this technology they are taking about using a very small nmber of spins to do logic and represent data.
Pun not intended.
Noticed something in that article - they state that the hard disk read heads use GMR sensors - not quite accurate. They use a single unit spin valve. GMR devices consist of many layers stacked on top of each other, and, more pertinantly, they operate at large magnetic fields. The sensor used have a lower field for peak sensitivity, and the change in resistance in smaller. GMR is conventionally used in the literature to indicate large, multi-layer devices. [0]
One thing that the article glosses over slightly is the difficulty in construction. Well, it's not so much a dificulty, as a paradigm shift. The metal GMR structures are built vertically onto a substrate, and thus the working current flows perpindicular to the plane of the substrate. This is distinct from traditional semiconductors, where the principle direction of the working current is parrallel to the plane of the substrate.
The notable exception would be the spin FET, but they've not actually been built yet, so it's a little tricky to comment on.
One option that the article didn't mention is the possibily of generating a magnetic semi-comductor / metal by using a conventional magnetic insulator (such as NiO, MnO or Fe2O3), and dopeing, or otherwise adjusting the electrical properties [1].
My research is into combined ab initio and statistical mechanical models of ultra thin films of the magnetic insulators. Particularly interesting is what happens when a two atom thick layer of iron is put over an NiO surface - spin dependant electron transfer, which is interesting. All in all, most of my work is the blue sky / basic building block level.
My point is that the spintronic devices require a finre degree of control in construction - by thier nature, the magnetic structure is important. Oh, and as a kicker to this, the length scale for a defect in a magnetic lattice is around 20 or so times larger than it's affect on the electrical properties. Additionally, it seems likely (to me) that other routes to mass manufacture may have to be found.
In other words: These are going to cost more. Not just because they are new, but also because they are inherently more complicated devices that electronic semiconductore devices.
[0] Well, in PhysRev anyway. IEEE and similar may use a different nomenclature
[1] My calculations suggest that a layer of NiO 4 formula units thick, or thinner, will be a metal.
That was almost as funny as my joke.
Karma: Good (despite my invention of the Karma: sig)
No, they use Spin-dependent electrons. This is spintronics, in a nutshell.
Up until now, almost all electronic devices have made use only of the electronic charge. Ie, amplifying it, switching on it, transferring it, etc.
Well, in a subtle manner, there is spin dependence in the above, due to Pauli exclusion, but that's buried in the quantum statistics.
Remember the electron is a spin-1/2 fermion, and hence has two possible states for a measure of it's spin in any given direction. Spin is an inherent property of many particles, with no classical analog, but you can think of it roughly as an angular momentum. Spin is quantized, unlike a spinning top. A spinning top is a classical system, which can have any rotational speed from 0 to any positive/negative values. (Negative means opposite direction of spin as a positive value).
Since the electrons are quantized spin-1/2 particles, there are only two measures of the spin angular momentum that are valid. +-(1/2)hbar where hbar is the Planck constant. Thus, an electron can only spin one way or another, there are no intermediate values (including no zero value, so it's ALWAYS spinning). Also note that this spin doesn't really represent the electron spinning about it's own axis, it's an inherently internal concept that's is actually quite involved.
These two values of spin of an electron can now be exploited in new devices. Right now the goal is to make devices that can inject electrons of one value of spin, and make transistors that work only for certain values of spin, or preserve spin parity, etc. Quantum computation would work nicely here too because the two states of spin are a good basis for representing a binary digit.
I haven't read the Scientific American article, so I don't know if I'm just repeating the obvious or not. But I'm a graduate physics student right now, and I hope to eventually work on some applications of spintronics. It is a currently buzzing field with much potential.
make world, not war
Sounds like the perfect chip for spindoctors to use. :)
Video Game cheats, hints a
I'm sorry, but the experimental data is inconclusive at this point. It may very well allow FTL data transmission. Besides, it's not like one of the hobbyist uses for this will be realtime control of Kuiper belt probes. It's moot.
QE won't allow near perfect encryption. What it will allow is a transmission medium that is untraceable geographically and one that is eavesdrop proof.
But then, it may not even be that. Unless you manufacture these things yourself, under direct supervision, there is no way to know that the gov hasn't placed a second pair of QE particles in the device... sure, you can open it up and look, which collapses the damn thing. Besides, why would you want to distribute keys anymore? So you can talk safely over the phone? Hello McFly, assuming that you can trust the QE transciever in the first place, just speak over it... eavesdropping is impossible.
But I can see how it would be cool to connect QE pairmates up to gigabit ethernet transcievers. Just plug it into your switch, and you have perfect wireless networking that is without distance or interference limitations.
"FTL isn't moot - it's what the original poster said he wanted!"
What, a dozen people in history have been as far away as the moon? Which has a 2000ms ping time. The original poster most certainly doesn't live there, so FTL information transport probably isn't a priority of his.
I'm not even sure what you're talking about any more. OTP's are easy to come by, it's distributing them securely that is a problem. So you buy your little black box that in theory lets you recieve the OTP securely. Big deal
Another device hidden inside, watches the signal as you recieve it. Not in the middle where it collapses. Besides, if QE allows secure OTP transmission, send the message that way, unencrypted.
QE photons and what not are much easier to come by, but not as fun. I've read hints that more docile particles might be subject to QE, in such a way that they could refrain from collapsing even after seperated by any distance. In such cases, it might be possible to send data using these as a transmitter and reciever (for duplex, you'd need 2 pairs). Figuring out a way to do this so that you could send info without collapsing them would be difficult, likely impossible in practice. I've heard stuff to the effect that this may indeed be instantaneous, or still subject to FTL. Either way, who cares? It would still kick ass. Any point on the globe is never farther than what, 8000 miles or so from you? That's an acceptable ping time in my books.
I believe you're referring to using QM to send a signal that can be intercepted, but in doing so betrays the eavesdropping (since the eavesdropper can never make a 2nd fake signal that will match the first). This has been performed with photons over both fiber, and through the air. Cool, but nothing I really care about.
So that others have a clue what we're even talking about, the layman's explanation of QE is tricking 2 or more particles into believing that they are the same particle, at least as far as certain properties are concerned. Push one particle, the other also moves, etc. More than likely, it's science fiction (I think Ender's Game was the first I've read to use this premise). But then what tech isn't scifi before it's invented?
Oh I see. The whole problem has always been that we can't *make* OTP's. You're a very subtle and elaborate troll. Can't believe I've been an idiot this long.
Never, and I mean ***NEVER*** has it ever been described to me that OTP's are difficult because of a randomization problem. Sure, many general rand()'s are far from the quality needed for OTP. But this doesn't rule it out. Using wav files of static noise are generally high enough quality, using the hardware rand() in a Pentium 3 is even better. The coin toss problem has been fixed...
It's getting the OTP (one time pad, if I've not explained it yet) to the other person securely that has ***ALWAYS*** been the problem.
So I think it's you that is confused, not I.
QM does allow for safe OTP distribution, but this can still be eavesdropped on. It just makes it obvious to the encrypters that someone is eavesdropping, and that they need to try again before sending the important message. This method has little, or nothing to do with QE, that I am aware of.
And my laymen's explanation of QE is still better than yours, if far from perfectly accurate. The gist of it remains the same. You know, you actually had me for a second, checking to be sure I wasn't brain farting, and using the term QE when I really meant something else. Fucking trolls.