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Physicists Watch Individual Electrons Flow
SG writes "Physicists at the Tokyo Institute of Technology have developed the world's most sensitive ammeter yet. The device allows current to be measured at the attoampere level and is expected to be of use in nanoelectronics, calibration devices, quantum computation and biology."
Here's a picture of the ammeter in action.
Would be nice if this could mean gigapixel cameras & the answer to the age old question of ghosts.
Wanna fight ? Bend over, stick your head up your ass, and fight for air.
RTFA.
The device could be used for a wide variety of applications, including nanoelectronics, calibration devices, quantum computation and biology (Science 312 1634).
And that was in the first paragraph. It took you longer to type your post than it would have to actually read the first paragraph. And you even forgot to yell 'frist post.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
For the likes of Intel, this is the hardware equivalent of gdb.
It's a government plot to keep track of stray electrons in order to prevent terrorism. ...tinfoil hat firmly in place (gotta protect myself from stray electrons)
I reserve the right to think for myself. Others' opinions are optional. Puppy on lap = typos...not illiteracy.
With utmost seriousness...
Why Not?
Would it have to change the flow by measuring it? How much by pure quantum "observation" effects?
As a non-phyisics grad (Computer science), I'm wondering.
Ryan Fenton
So now ol' Ben Franklin can finally see which direction electrons really flow!
Just because it can't be explained doesn't mean it isn't true. Science fits into reality... not the other way around.
My question is if I want to measure current (assume an ideal current source) then I will hook it up to this new invention. The mechanism of current in this new measuring device is quantum tunneling. Is there any reason that the current source in question employs the same mechanism. It may still be conventional drift-diffusion with very very low fields (and probably very low mobility). Now when I interface it with this double-quantum device, does the change in mechanism ensures current quantity ? If answer yes, what is the intutive answer. I can understand current continuity when it is drift and diffusion.
It's alright. I'm sure there is no electrical activity in your brain. You're safe. :-)
The parent might deserve a "funny" rating, but not "informative". Whoever modded this informative did so without actually checking the link.
The real "Libtards" are the Libertarians!
Sure there is! I lick 9 volt batteries all day.
I reserve the right to think for myself. Others' opinions are optional. Puppy on lap = typos...not illiteracy.
Nanoelectronics, calibration devices, quantum computation.... and the world's smallest abaci.
When the posters fear their moderators, there is tyranny; when the moderators fears the posters, there is liberty.
I can think of a lot of smart, witty, even sarcastic jokes about this article... but this is truly a 'Wow' moment if you fully understand the implications of this.
7h3$3 4r3n'7 7h3 Ðr01Ð$ ¥0 4r3 £00|{1n9 f0r. M0v3 4£0n9. --OB1
Before you read any of the article and just say the headline: "Physicists Watch Individual Electrons Flow" did anyone think of a bunch of guys in white lab coats looking down at a table with money in their fists betting on electron races? Because I did... And boy was it disturbing... Gambling physicists can be very rude. (At least the ones in my head are)
Eating the brains of your enemies does not make you smarter. But it's still fun.
Just because it _may not_ be of any use today does not mean that it will always be "useless". The parabola was known to the ancient Greeks but it only saw its first "practical" use in the hands of Galileo Galilei who used it to predict the trajectory of cannon balls.
Two roads diverged in a wood, and I - I took the one less travelled by. (Robert Frost, 1916)
Physicists Watch Individual Electrons Flow
n e.shtml
-in other news... Physicists discover new uses for the psychotropic http://www.erowid.org/chemicals/mescaline/mescali
no way is this flamebait. original poster is clearly a first post troll.
that we can finally see just what happens with that light box experiment with waves/particles of light?
Someone with a clue help me out here. Does this mean we'll get a definitive answer on how a single particle of light can actually be in two places at once?
I am a leaf on the wind
Am I the only one to notice that that would be full of TITs ?!?!
Sigh...I need to get some soon.
At least not until you get into wave or string theory stuff and that's based on the very thing you're trying to look at so not exactly going back to basics.
The problem with quotes on the internet, is that nobody bothers to check their veracity. -- Abraham Lincoln
and the rest of us are forced to watch GOLF on TV.
The problem with quotes on the internet, is that nobody bothers to check their veracity. -- Abraham Lincoln
http://www.analogzone.com/tmt_0912.pdf
get over it, hippy. the original poster should get modded to negative two and have his right to post on slashdot taken away. so should yours.
Except that charge is what's moving, not necessarily electrons.
"Physicists at the Tokyo Institute of Technology..."
Wow. Nice, TITs.
The IRS is the one organization that you don't want to fuck with. Remember, these are the guys who took down Al Capone.
For an unknow reason, their device automatically falls into sleep mode after having counted too many electrons.
What about that Greek fire death-ray thing they used to torch enemy ships? I thought it was speculated to be a parabolic mirror.
Read the fucking article summary, you idiot. Do these physicists need to explain themselves to every random, layman slashloser?
We've harnessed the power of CSI!
In case you didn't know, "flow" is physicist slang for "sexual intercourse". They're watching electrons "get busy". Yeah, they're pretty sick and twisted, but I supposse I would be too if I had to hook car batteries up to my nipples all day in the name of science. If you don't believe me, just RTFA and find out.
A computer once beat me at chess, but it was no match for me at kick boxing.
but can they hustle?
Actually all particule exhibit that duality. I worked for the labor which made the first scattering of an electron through a germanium crystal (I think it was germanium at least).
C. Sagan : A demon haunted world:
http://www.amazon.com/gp/product/0345409469/
visit randi.org
The big one, I think, will be allowing the SI definition of current to be changed from the present unwieldly method of "an ampere is the steady current that when flowing in straight parallel wires of infinite length and negligible cross section, separated by a distance of one meter in free space, produces a force between the wires of 2 × 10-7 newtons per meter of length", then defining the Coulomb as "the charge delivered by a current of 1 ampere in 1 second".
The new, accurate electron counting capability alows the quantum of electrical charge to become the base unit, as it should be, and then to define current as the number of charges per second.
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
Comment removed based on user account deletion
You changed the results my measuring it!
The revolution will not be televised... but it will have a page on Wikipedia
"what practical application could this have"
Occording to TFS:
"and is expected to be of use in nanoelectronics, calibration devices, quantum computation and biology"
So are you actually asking why any of those would be useful?
The revolution will not be televised... but it will have a page on Wikipedia
I always thought it was a waste to have all those electrons flow just to represent a '1' instead of a '0'.
:)
Now they only need one electron - cool
Max.
Finally!
Something I can measure it with!
Thank you, God!
Muhaha!
It's alive! It's alive!
Yeah, they're pretty sick and twisted, but I supposse I would be too if I had to hook car batteries up to my nipples all day in the name of science.
You mean your TITs, don't you?
You are correct, of course.
There is more than that though - it is a wonderful thing, to be able to seek knowledge for knowledge's sake. Always there is this emphasis on a reason for learning about the world around us. It doesn't have to be that way. There is a joy to be found in discovery, regardless of the implications. This is an important thing.
What would be the gain-bandwidth for a current amplifier built with this technology?
When you get down to zepto and yocto, that's when things really start happening!
I've got your sig, right here.
It's not the stray ones you have to watch out for - it's the ones that are meant for you.
How exactly is this "watching"?
Beetle B.
Ahh, the wayward electron...
It must have been something you assimilated. . . .
And maybe he couldn't see the summary either. Of course, that raises the question of how he managed to post here.
No but it can accurately calculate your power bill.
Justice is the sheep getting arrested while an impartial judge declares the vote void.
The whole business about what is being observed is somewhat academic. We don't really know that any of these things exist as such, but only that the world seems to behave as if they did. We have no way to perceive reality directly, but only to probe how she behaves indirectly.
And that's good, because it means that we can throw out old theories with impunity once better ones are devised. If we were to ever observe the TRUTH, we would no longer have the freedom to do that, and it would be the end of Science as such.
Because you can study the physics of smaller and smaller systems. There are only a few areas that this device will be useful, but researchers are always fighting against noise while trying to increase the sensitivity of their devices.
Up until now the record for smallest current was about 100 attoamps with a dc squid. The great thing about them is that you can detect currents from 100 attoamps (if you're very, very careful) all the way up to milliamps, all in the same device in the same setup.
This new device with coupled quantum dots will only work on the attoamp scale, so is not as versatile, but the years of work that went into designing, fabricating, and measuring this device is astounding.
Think about it, they are measuring individual electrons, they are fighting against a huge number of electrons surrounding their devices, which experience random thermal noise. The thermal noise in the shielding around their device can generate eddy currents of the order of what they are detecting so they had to account for that too, and design special shielding.
Not only that, they have to think about the coupling of the quantum dots. You only want charge transfer from resonant tunneling, if the dots are too strongly coupled to their surroundings the quantum coherence is swamped, the linewidths of the levels being populated would be broadened too much. And if they are not coupled strong enough, you won't get enough resonant tunneling.
Of course there are a lot more considerations, going from concept, design parameters, actual method of fabrication and preparation, detection methods, and noise and data analysis.
All in all it's a great technical achievement to do what they've done.
What a waste of money. The other night I drank one $7 bottle of sake and I was able to see individual quarks moving.
If the geiger counter does not click, the coffee, she is not thick.
. . .says the man posting as AC. Get an account, all of you, and stop hiding as AC!
Hey, can I bum a sig?
Also, isn't it that the collapse of the wave function depends on what you put after the barrier?
That is, if you put a single particle detector at one of the slits (or a very sensitive screen), you will get "pings" that eventually "build up" to show the interference pattern fringing. However, if you put a particle detector in front of both slits, the "fringing" disappears - implying the wave function has collapsed and no interference pattern results (because the particle can only go through one of the slits at a time). If I understand it it correctly, this is the essence of the Copenhagen Interpretation.
There seem to be other interpretations of this phenomena as well. The Wikipedia article on the Double Slit Experiment goes into great detail, with a lot of links to bring you up to speed on this fascinating subject of QM...
Reason is the Path to God - Anon
Didn't a physicist (namely Millikan) already see a single electron flow from one place to another when he did his famous oil drop experiment (about 100 years ago?) that measured the mass of the electron?
...the future crusty old bastards are already drinking the Kool-Aid.
It's not likely. Why would you want a parabolic mirror to torch ships? You'd have to wait for them to be exactly the right distance to hit the focus!
Millikan suspended charged droplets of oil between too plates.
:P
When he got the electric field at the correct value the gravitational force (F = m*g) was canceled by the force due to the electric field (f = q*E)
What he actually measured was the charge on each droplet, and found that the lowest common factor was -1.67 e-19 (i.e 19 zeroes infront of 1.67, 0.00....0167)
How he did this was he dropped the oil drops from above, measured their terminal velocity, and from this, their mass. To charge the oil drops he illuminated the chamber with x-rays, ionising both the air, and the oil drops.
He then applied a voltage across the two plates (one above the oil drops, the other below).
So at all times, he was measuring the charge from a large number of electrons. It's not commonly known, but Millikan knew what he was looking for in his dataset, and from what I've heard the quality of his data was poor, and ignored a lot of fractional datapoints (I can't prove this, it's only geek gossip I heard).
Hope this answers your question.
To detect single electron currents, you need to use modern technology (google d.c. squids, or even SQUID detector). For a long time Superconducting Quantum Interference Devices were the only detectors that could detect individual quanta (magnetic fluxons). Sorry I'm not going into the details of this, but I gotta pee
That's it, game over. Give that man the prize for best post of the day.
generally minority carriers means the less common of conduction band electrons or valance band holes, but holes aren't physical items they are just representative of missing electrons (a good analogy for hole current is moving your overdraft from one bank to another, its still money thats moving between banks).
the only things that carry charge in a normal conductor are electrons, ions can also do it but only really in soloutions afaict.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
Well, the whole thing is conjecture. But as to the involvement of parabolic mirrors, some have the idea that an array of flat mirrors arranged in a parabolic shape and that the array was somehow quickly and smoothly able to be changed so its focus changed. At least, that's one story I've heard about parabolic mirrors in relation to the ship burning device.
Of course others have proposed that parabolic mirrors were used to focus onto single flat mirros... and if that doesn't sound like it would work, good because it wouldn't.
The only feasible arrangement of parabolic mirrors whereby a device is created that can quickly change its focus is one which involves two parabolic mirros and a flat mirror that is on a moving mount. The one parabolic mirror focuses light onto the flat mirror(or partiaally focuses it depending on specifics) the flat mirror is mounted in front of the other parabolic mirror such that the focused light from the first is reflected onto the second parabolic mirror. This arrangment is similar to a parabolic transmitting dish. The flat mirror must be mounted so that it can move towards and away from the second parabolic mirror and the first parabolic mirror must be mounted so that it's angle can be altered to track the flat mirror.
In this set up, moving the flat mirror out moves the focus of the light inward and moving the flat mirror inwards moves the focus out.
I don't claim this is efficient, good enough to burn ships, what was used(if it was actually done at all), or that the tech existed at the time to do it. But, it is a method using parabolic mirrors to focus light at an arbitrary distance.
Of course, as I don't claim efficiency and the like, this doesn't apply to your claim that it is unlikely. In fact, I agree. I just thought it was an interesting arrangment...
The primary evidence that people use to suggest Millikan knew what he was looking for were vague margin notes about particular data being close or some similar phrase. If I recall, they could simply be quick notes about how well he thought he performed the experiment for a given datum. I think he ended up taking the measurement he liked the most rather than averaging them or something like that. Meh, this is all stuff I gleaned from one of those Discovery shows or the like about him... Though, I really wasn't awake through most of it, anyways... So, have a heapin' helpin' of salt w/ this one...
Also, the contraption he used for his experiment is quite a sight, though a cursory search didn't turn it up...
I can remember from my Lab days (boy, has it been really 20 years?!) a Burr-Brown amm-meter that had an electron-count mode where it would display "electrons per second" (actually unit-charges) instead of femto-amperes. Sure, it only counted in about 100-electron steps, but I think that's fair enough... :-)
that sounds pretty accurate.
cool
It's an interesting topic. I don't remember hearing much about people trying to figure out how it was actually done until the last few years, when everybody seemed to come out of the woodwork with a theory.
I think the various many flat shields theories are probably the most likely. It would be pretty hard to make a monolithic parabolic mirror big enough and it's not something you'd just have lying around. Nicely reflective shields, on the other hand, are handy for blinding, distracting and intimidating in regular battle as well.