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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.
Im ready for Quantum Entanglement Networking, heh zero ping time, and nearly unlimited bandwidth, and unlimited range, till then im gonna be stuck with dial up, seeing as how i live on the outskirts of nowhere
"The United States has no right, no desire, and no intention to impose our form of government on anyone else." - Bush 05
Electronics use electrons, so spintronics must use...spintrons?
Karma: Good (despite my invention of the Karma: sig)
...the foundation of spintronics... wasnt the foundation of spintronics and 80's techno group?
No, wait. That was before.
With your feet in the air and your head on the ground, try this trick and spin it.
Your head will collapse if there's nothing in it and you'll ask yourself:
Where is my mind?
Then a strange chip would be perfectly normal!
You are not the customer.
Hehe, I would give you +1 Funny if I could.
Spintronics??? I had the idea of sticking my computer in the washing machine months ago. If only I'd patented it.
quantum computing?
we already have that:
fork()
DNA is the ultimate spaghetti code.
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.
Will us nerds who do tech support begin to be called spin-doctors by the press now?
"The United States has no right, no desire, and no intention to impose our form of government on anyone else." - Bush 05
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!
Of course you will have to power it via the static electricity generated while using a hula hoop while wearing a polyester leisure suit.
--
As a matter of fact, I am a lawyer. But I play an actor on TV.
A little static electircity changing an electron or two in your computer, and you'll have to re-authenticate it.
I miss the old Scentific American, when the articles were more technical and more accurate.
...where the executives used the spin of "stock options" to perform their functions.
I'm not familiar at all with the field, so here's a dumb question:
If they are going to use electron spins to keep track of information, how are we to encapsulate the electrons, with other electrons? Didn't the article say that they affect all other electrons in the area?
since they're spinning, do the electrons get sick and barf up their nucleus?
-motardo
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.
Coming to the diagnostic section of your local software store in 2035: Norton Spin Doctor 1.0
"What is the sound of one belly slapping?"
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.
Here is a solution of that problem and how these two mcse sys admins routed around the problem by constructing a crude lathe to be used as a rudimentary weapon.
For a fairly detailed overview of quantum computers, see Brian Hayes' article "The Square Root of NOT".
The mind boggles at the power of a quantum parallel CPU and that's before some smart arse overclocks it.
I am a Karma Library.
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.
Instead of 0s and 1s we'll have +1/2 and -1/2!
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
"For instance, even the earliest computer hard drives used magnetoresistance--a change in electrical resistance caused by a magnetic field--to read data stored in magnetic domains."
All earlier practical Hard Drives before the "discovery" of the GMR effect used Electromagnetic heads; wildly different practicalities than GMR heads. They were simple electromagnetic devices mounted on aerodynamic substrates; low impedance, wire wound affairs and definitely NOT magnetoresistive.
Did I miss something in the spin and magnetism physics relationship??
Sounds like the perfect chip for spindoctors to use. :)
Video Game cheats, hints a
...the possibility of microchips which use the "spin" of an electron to perform their functions.
I thought that was the basis of quantum computing? At least when I read about it 2 years ago it was..... called a qbit?
Everybody is talking about building quantumcomputers, but no one has thought of a way to stop the distorsion that occurs when making an electron spin. The are multiple ways to make it spin, on of them is using a magnetic field. This will influence the electrons nearby. Other methods do have the same effect. There are two ways to deal with this: 1. Find a method that will not create distorsion. So far, no one has been able to come up with a good solution. 2. Compromise the distortion in the software. This will reduce the extra speed, gained by using the quantum mechanics, to almost nothing. Therefor, untill we find a way to make the particles spin in one or two directions without influencing the others, we will not be able to use all the extra speed. Distorsion is not the only problem. The order in which the particles are made to spin will also influence the state of the particles. I didnt' read the article, so if this has been sad already, I'm sorry.
When'll linux try to assbackwords enginere the software get a half ass driver and be a mediocre OS at 400x the speed?
Only half kidding:
Imagine that programs
in a quantum computer can have bugs that
disappear as soon as you try to observe them.
In current programming there are sometimes problems that disappear as soon as you try to debug them, the disappearance apparantly caused by the interaction with the debugger program.
These bugs are called "Heisenbugs".
It just appeared to me that quantum programs could have actual Heisenbugs.
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UNIX isn't dead, it just sme