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More on Spintronics
segment writes "'We have discovered the equivalent of a new 'Ohm's Law' for spintronics - the emerging science of manipulating the spin of electrons for useful purposes,' says Shoucheng Zhang, a physics professor at Stanford. 'Unlike the Ohm's Law for electronics, the new 'Ohm's Law' that we've discovered says that the spin of the electron can be transported without any loss of energy, or dissipation. Furthermore, this effect occurs at room temperature in materials already widely used in the semiconductor industry, such as gallium arsenide.'"
so... they've figured out how to alter the path of electrons outside of a circuit. I can see how that could be useful, but how likely is this to be practical to real electronics?
In Soviet Russia, the electron spins you
[Fuck Beta]
o0t!
Man it seems like that stuff NEVER goes away. Haven't we invented 10 technologies to get rid of that stuff already?
Wouldn't the free manipulation of information be sorta, I dunno, against the laws of thermodynamics?
dawnlevy@stanford.edu
650-725-1944
Stanford University
'Spintronics' could enable a new generation of electronic devices, physicists say Moore's Law - a dictum of the electronics industry that says the number of transistors that fit on a computer chip will double every 18 months - may soon face some fundamental roadblocks. Most researchers think there'll eventually be a limit to how many transistors they can cram on a chip. But even if Moore's Law could continue to spawn ever-tinier chips, small electronic devices are plagued by a big problem: energy loss, or dissipation, as signals pass from one transistor to the next. Line up all the tiny wires that connect the transistors in a Pentium chip, and the total length would stretch almost a mile. A lot of useful energy is lost as heat as electrons travel that distance.
Theoretical physicists at Stanford and the University of Tokyo think they've found a way to solve the dissipation problem by manipulating a neglected property of the electron - its ''spin,'' or orientation, typically described by its quantum state as ''up'' or ''down.'' They report their findings in the Aug. 7 issue of Science Express, an online version of Science magazine. Electronics relies on Ohm's Law, which says application of a voltage to many materials results in the creation of a current. That's because electrons transmit their charge through the materials. But Ohm's Law also describes the inevitable conversion of electric energy into heat when electrons encounter resistance as they pass through materials.
''We have discovered the equivalent of a new 'Ohm's Law' for spintronics - the emerging science of manipulating the spin of electrons for useful purposes,'' says Shoucheng Zhang, a physics professor at Stanford. Professor Naoto Nagaosa of the University of Tokyo and his research assistant, Shuichi Murakami, are Zhang's co-authors. ''Unlike the Ohm's Law for electronics, the new 'Ohm's Law' that we've discovered says that the spin of the electron can be transported without any loss of energy, or dissipation. Furthermore, this effect occurs at room temperature in materials already widely used in the semiconductor industry, such as gallium arsenide. That's important because it could enable a new generation of computing devices.''
Zhang uses a celestial analogy to explain two important properties of electrons - their center of mass and their spin: ''The Earth has two kinds of motion. One is that its center of mass moves around the Sun. But the other is that it also spins by itself, or rotates. The way it moves around the Sun gives us the year, but the way it rotates around by itself gives us the day. The electron has similar properties.'' While electronics uses voltage to move an electron's center of mass, spintronics uses voltage to manipulate its spin.
The authors predict that application of an electric field will cause electrons' spins to flow together collectively in a current. The applied electric force, the spins and the spin current align in three different directions that are all perpendicular to each other (see film of the effect at http://news-service.stanford.edu/news/2003/august2 0/zhang-video-820.html).
''This is a remarkable thing,'' explains Zhang. ''I push you forward and you move sideways - not in the direction that I'm pushing you.''
So far, only superconductors are known to carry current without any dissipation. However, extremely low temperatures, typically -150 degree Celsius, are required for the dissipationless current to flow inside a superconductor. Unlike electronic superconductors being investigated in advanced laboratories throughout the world, whose operating temperatures are too low to be practical in commercial devices, Zhang, Nagaosa and Murakami theorize that the dissipationless spin cur
[Fuck Beta]
o0t!
Superconductors anyone? If we could figure out a way to transfer some of the spin to linear motion at the end of a wire..
YEA BABY!
The applied electric force, the spins and the spin current align in three different directions that are all perpendicular to each other ''This is a remarkable thing,'' explains Zhang. ''I push you forward and you move sideways - not in the direction that I'm pushing you.''
Same thing happens with me after about a six pack.
Hey, thanks for having a sense of humor. It is a funny word. Consider making some effort to get over yourself.
-Peter
OK, I RTFA, and it wasn't what I was expecting.
Isn't it a property of these kinds of things that you can seperate two electrons (or some subatomic particle, can't remember) and change one's spin, and the other, no matter how far away, will instantly change? I recall an experiment in which this worked over a distance of six miles. Wouldn't this be the perfect interconnect? No wires at all?
...My physical electronics prof (who has over 80 patents in chip fab) told us that germanium had certain problems in collecting electrons. Which is why gallium hasn't gone away yet. But I'm not 100% sure (it was a while ago) so I could very well be wrong.
To make laws that man cannot, and will not obey, serves to bring all law into contempt.
--E.C. Stanton
Ohm's law is "voltage dropped across a load is directly proportional to the current through the load, for a constant load". What does this have to do with the law the article talks about?
Jason
ProfQuotes
Communication faster than teh speed of light that is very slow.
In theory you take a rod that goes from one galaxy to a distant galaxy many many lighyt years away. With a slight movement on one end of the rod, ina back and forth movement, the other end moves, effectively allowing communication based upon movement. Movement that is far slower than the speed of light but able to communicate to distances beyond the limitation of the speed of light.
Of course that is a simple theory only to communicate the concept of accomplishing something in a different way that is not possible on other ways. Like tryingto do advanced math using roman numerals instead of the decimal system that includes the zero place holder.
So does this spin thing make it possible to achieve antigravity or super conductivity in common use? If so, then aren't there other human resistance factors to deal with that may be more difficult and non-natural to have to deal with and overcome?
It took 300 years for the Hindu-Arabic decimal system to propogate thru the constraints of the roman numeral system supporters, regardless of the improvement in ease of math that was made possible, not to mention the technology that needed it, to be come a reality (computers).
Probably more funny in the UK and Australia than in the US though. Unless you wanted to pronounce it "Gallium Assinide".
--Fesh
Kill -9 'em all, let root@localhost sort 'em out.
that with Spintronics they can make James Blish Cities in Flight type Spindizzies yet?
One line blog. I hear that they're called Twitters now.
Reading the article make me recall how I believe that the cooling of some elements to achieve superconductivity is in reality just the syncing of the relative atomic speed of the elements involved.
This spin issue seems to suggest syncing as well, but without the concerns of tempature constraints below room tempature.
In maybe a 10-year timeframe, spintronics will be on par with electronics
If the actually manage to go from idea to commerically competitive "spintronic" circuitry in only a decace, I'll consider that proof of some sort of space-alien technology transfer deal going on.
Gentlemen! You can't fight in here, this is the War Room!
I had a prof in college who loved to tell the tale of finishing his bsee at mit, and didn't know what to do next. Being young and stupid (his words) he went down to the army recruiting office and inquired about electronics. The guy behind the desk says he has to come back the next week to take a test.
So, he shows up with a bunch of other hopefuls (again, his words), and takes the test. One of the questions is 'state the 3 forms of Ohm's law." As a good ee, he immediately writes down 'V = IR', no problem. Thinking (!!), he remembers there is a form involving current density, and sets about to derive it (in class this included the steps he took). Now, a third form. He drew a blank, so went and finished other parts of the test.
Coming back to this question, he's suddenly inspired by remembering something based on magnetic density in a coil or transformer. Again, he sets out to derive the equation, but the guy giving the test says 'times up' before he can finish.
The next day, he heads back to the recruiting office, and asks how he did. "Great," says the sargeant, "but, what was up with the Ohm's law question?"
"Oh, the standard form, and then experessed in current density, and...."
"Nah, all we wanted was V = IR, I = V/R, and R = V/I."
Proof of, once again, that engineers, like musicians should not try to be funny.
'ta
No system can be 100% efficient, not now, not ever. The mere fact that they would make the claim of no-energy loss whatsoever is all that it takes to set off the alert flags that this is nothing but a hoax.
File under 'M' for 'Manic ranting'
Spin is an intrinsic, unchangeable quantity for an elementary particle. Particles with half-integer spins are called fermions, while particles with integer spins are called bosons. Fermions can only be created or destroyed in particle-antiparticle pairs, whereas bosons can be created or destroyed singly.
Whenever the offence inspires less horror than the punishment, the rigour of penal law is obliged to give way...
I think the word your looking for is sketchy. I read the piece and wondered how this got to slashdot. This is so obviously a piece to get funding for further research from a couple of quacks you can't even explain the process.
-You know its like the earth orbits around the sun and then spins on its access that's how it works.-
Give me a break they are trying to lure in the gullible who know nothing about electronics to give them money. I think the idea of spintronics is great but what they propose is not worth anyone's time there are plenty of others who are doing valid research in this area. If the best they can explain is a planetary analogy or some sort of half assed flash animation then check someone else out.
So donate today to the EFF - the Electron Freeing Foundation!
Maybe now O'Reilly can finally deliver on his 'no spin zone' promise.
Of course, if all his electrons stopped spinning it would probably be the most interesting televised farewell I've ever seen.
or did you write this?
Reminds me of a famous saying: gallium arsenide is the technology of the future, and will always be the technology of the future.
15 years ago, Cray tried to build supercomputers (the Cray 3 and Cray 4) around gallium arsenide semiconductors. Though he did manage to make this technology work, the difficulties of designing and manufacturing in (what was then) a radically new technology resulted in a product that was late to market and, ultimately, the company went under.
GaAs is used in some specialized applications - like the RF sections of cell phones. But it never managed to take over in high speed digital.
So here we have yet another prediction that GaAs has properties that make it desirable as the technology of the future - but will past historical trends continue forcing it to always remain the technology of the future?
The real question is, what is 'spin current', and how does it relate to the conventional definition of electric current.
"Nothing exists except atoms and empty space; everything else is opinion." - Democritus
V=IR
I=V/R
R=V/I
My space heater is 100% efficient, so sure, why not?
Oh... you wanted useful energy conversion.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
Spintronics is promising, but I doubt that it will be the NBT. Quantum-dot Cellular Automata (QCA), which encodes binary information based on electron orientation, seems to hold more promise. It is highly scalable, small, can hybridize with CMOS, and can already be fabricated at low temperatures. With the addition of clocking regions to lower inter-dot tunneling barriers, even pseudo-pipelining is realizable. Perhaps the best thing about this is that it all cells are coplanar! I just attended a conference (IWQDQC) on Quantum Computing, and believe me, spintronics faces its share of problems.
everyone talks about soviet russia like it was a bad thing... at times it seems like its better to "be pointed in the right direction" then attempt finding it yourself. have you tried being a sore thumb? do u know how fast you will be crushed into submission by neighbouring domains?! why bother, it takes too much eV to be a rebel.
If you're messing with electron spins, forget superconductivity and that stuff.
I want a Spindizzy.
(ref: James Blish, "Cities in Flight")
The living have better things to do than to continue hating the dead.
First, got to get my trolling out of the way. Man, this sounds like a scam to setup for future bogus patents. I'm not saying this application isn't real, just that it smells like a case of researchers setting themselves up to benefit commercially by calling a known concept 'neglected' and giving the study of it a fancy name. I'm not even doubting that they've found a combination of compounds that minimizes energy dissipation in integrated circuits.
My real statement is that even if this is leads to better integrated circuits by minimizing energy dissipation, it won't nullify the fact that the energy will still have to dissipate from electronic devices at some point. In the case of a computer system, would this mean that other components would have to deal with increased heat rather than the situation we have now--CPU overheating?
Because so many people complained about the "ad" earlier and the lack of real news that was actually for nerds. Unfortunatly, you can't please all the slashdotters even some of the time.
This Space Intentionally Left Blank
You think that a news release covering a article in Science isn't going to be dumbed down? Or that Dr.Shou-Cheng has managed to fool Stanford, Santa Barbara, and IBM with his slick descriptions of 'imagine a planet orbiting around the sun'. Or possibly you have a better explanation of quantum spin that will eludicate the masses in 30 words or less?
"A language that doesn't affect the way you think about programming, is not worth knowing" - Alan Perlis
So instead a link to another "ad." You know there are plenty of other links related to spintronics that would have had more depth that this fluff piece.
"movement" of the spin of an electron, by the application of an electric field.
Angular momentum.
Maxwell's laws.
And this is where it's all hinged... The "sensitive spin detector". What is a "spin detector"? I still haven't seen or heard everything, but this gem is going to get a special note in my memory bank. How exactly does one measure the spin of an electron? How do you know that you've got your spin detector focused in on the correct electron in the first place? Just how sensitive is this spin detector? Is it as sensitive as my b.s. detector?
--
Pull the other one, and my pants will fall down.
I've re-read Cities in Flight at least three or four times and see this spintronics stuff would make the spindizzy engine work. All we need now is a way to break New York City free from it's base of bed rock, and send it on it's way. Then Washington, D.C. whilst Congress is in session, and I see a Win-Win situation here. Hell, let's just spin off the whole Northeast corridor from The Beltway to Boston and be done with it.
Too lazy to create a sig...
"And this is where it's all hinged... The "sensitive spin detector". What is a "spin detector"? I still haven't seen or heard everything, but this gem is going to get a special note in my memory bank. How exactly does one measure the spin of an electron?"
Simple. You use a very drunk physicist. Heads it's up, tails it's down. Flat on his back, the experiment's over.
Even that's not 100% efficient. Some of the radiation will be in the radio frequencies and escape by going through your wall and into space.
However, a heat pump (an air conditioner in reverse) can get 200-300% efficiency (2-3 joules of heat into your house for each joule of heat of electricity), but it still doesn't violate any law. The extra heat in pumped in from outside, and since heat energy has far more entropy than electricity, entropy is also increasing.
"materials already widely used in the semiconductor industry, such as gallium arsenide.'""
Kirk: Warp Factor Ten Scotty!
Scotty: I'm giving her all the gallium arsenide we've got Captain but she's suckin' mud!
You know you're a geek if you've ever replied to a tagline.
I'll believe it when I can order one from Digi-Key. :-)
--- Ban humanity.
He's just a news talk show host. I really can't find what all the animosity is about. It's bizarre.
If the children are already reading slashdot, there's really no hope for them. And anyhow, if the Soviet Russia jokes don't get them, Cowboy Neal will!
[Fuck Beta]
o0t!
The discussion on spin is wrong. Spin has nothing to do with the rotation of macroscopic objects like the Earth, it's an intrinsic quantum property of particles like the electronic with no macroscopic analog. The best explanation I've heard of spin that doesn't involve explaining the details goes like this: spin is a measurement of the number of rotations required to bring a particle back to its initial state. One-half spin particles, like the electron, require, counterintuitively, two full rotations to go back to their initial state.
The physical situation seems to have very little to do with Ohm's Law except in the loosest sense. They're describing a current consisting of electron spins under an external electric field. This has some interesting properties (I'd like to poke at the math, if I could read the paper), one of which seems to be that it is predicted to persist at much higher temperatures than the best superconductors. If so, because this spin current seems to be dissipationless, this would allow information to be transmitted without generating heat.
Interesting stuff; a pity the article was so poor.
For what it's worth, spintronics is already in use for disk drives.
From what I understand, the read/write heads of just about every modern disk drive are spintronics devices. Without them, we'd probably still be stuck with 1 GB disk drives.
I really don't know how that comma got there. I didn't intend it.
... to eliminate the harmful effects of Spin Doctors on their environment. Ehhh, well... can't have everything. *Goes back to surfing the web on his Sit-N-Spin* Mnem Ch-Ya! That'd like... Totally screw the pooch, babe!
Always has been, always will be.
Are you joking? How am I supposed to take you serious when you say 30 words and the article is clearly more like 750. Next neither IBM or Santa Barbara are mentioned in the article.
I took the time to track down the paper and read it in full I might understand the whole thing years from now but right now I have a few questions you might be able to help with.
I'm no physicist so I could be wrong but how can equations for linear motion describe rotational motion? The part actually intrigues me, according to the paper they are generating electric fields from the spin of the electron that is over unity. To me this would indicate they have potentially found an efficient way to transform heat energy into electrical energy. This to me would have been a story of worth if it had depth. This is slashdot after all and not CNN/MSNBC/FoxNews/Google News/.
Get me a transister, a flash light, a camera, and a CRT moma Ima gona spin me sum lectrons.
I had to dig but eventually found it at the following location. http://www.sciencemag.org/cgi/data/1087128/DC1/1
Well done? that guy's a fucking champion, dude.
The very first thing one should know about thermodynamics is that it only makes sense at macroscopic level. So please stop your nonsensical babbling.
-- Repeat with me: "There is no right to profits".
Perhaps more relevant to us is the fact that zero dissipation means, in effect, zero heat. It also means zero loss so power requirements, so important in the portable market, would lessen exponentially. Spintronics based devices would therefore not need the elaborate cooling solutions current semiconductors do. A truly silent computer may be just over the horizon, folks...
Resistance is futile. Reactance buggers it up.
So what's the "spintronics" formula?
In the last few years logic speeds have approached this, and you can now by GHz-level gates as part of the ECLinPS family.
make world, not war
"spin is a measurement of the number of rotations required to bring a particle back to its initial state"
Yeah, that's a particle's spin number. You don't think spintronics involves changing that, do you? That would be like changing an electron's charge.
There's a whole other kind of spin, which is similar to macroscopic rotation. That's why they call it "spin". It's not a perfect explanation, but it's close enough for the general public.
There should be a mod "-1 I Don't Think So, Captain" for people who critique science articles with Star Trek level technobabble.
another handy property of an electron is the ability to link it to another electron. by manipulating both electron spins at the same time they are linked. when one electron's spin is changed the other's is changed as well instantaneously. or so my physics professor claims. thus far there appears to be no dependance on distance. just think, instantaneous communications with a space probe using electron spin techniques, no more sending a probe out and then giving up on it when it goes out of communication range. since this technique does not use radio waves then you no longer have to worry about the blackout time durring space shuttle landing etc. etc. real potential here for massive technological jumps.
Red Hat is for people who hate Windows, FreeBSD is for people who love Unix.
www.putertech.net
You're an arsole.
Spread the pain... :-)
Karma: Excellent (My Karma? I wish...:-( )
If you're mystified by spin and quantum physics in general, This entry on ElectronOrbitals is a good place to start.
This is a new part of (or companion to?) Eric Weisstein's Mathworld. It's expanded now into Science World. Some of the references to electrons and spin are not yet complete, but there's enough here to get started.
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
It all depends on where you draw your control volume boundary (or mass), and how you define efficiency. If you define efficiency as energy into the device divided by heat energy into the room, then efficiencies > 100% are indeed possible with heat pumps as you describe.
I didn't get into this, but I also believe some electric heaters are far less than 100% efficient. In particular, the radiant heaters have poor efficiencies. How can that be?
I define my control mass as the air in the room. Radiant heaters heat anything with LOS to the beam. Much of that includes the walls and the floor. On a concrete slab, the floor can be a very effective heat sink. Windows are particularly bad.
The thing you notice about radiant heaters is that you get warm standing right in front of one, but as soon as you turn it off you get cold fairly quickly. Some radiant heaters add fans to help transfer some heat to the air, but that makes accoustic noise, and the transfer is over a very small surface area. Most of the heat is still radiant.
When I lived in a poorly heated apartment, I bought an oil-filled "electric radiator". This type of heater is cold when you first turn it on, which is probably frustrating for a lot of people, and discourages them from getting one. However, it has a large surface area and transfers all its heat directly to the air. Since it's sitting on the floor the heat rises and you get convection around the room too. Loss only occurs when heat is transferred from air-to-surface which is much less efficient than sending infrared beams directly to the surface, since only a small portion of the warm air contacts the walls at any given time, whereas the infrared beams go straight to the walls.
I would close the door to my room and 45 minutes later it would be warm and toasty. My room-mates with their beam heaters never had that kind of warmth. Better yet, since the air in my room was heated, it would retain the warmth long after the heater was off.
I used an electric timer to turn the heater on at 6 AM every morning. When I woke up at 7 I had no "morning shivers". The only problem was the low amps in our old place. Breakers tripped routinely... ah... those were the days.
I still have the heater boxed up in the basement of my current, adequately heated abode.
So pay heed young college students living off-campus! If you are in a cold old house like I was, stay away from those stupid little radiant heaters.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?