Individual Atom Memory Created 123
azav writes "University of Wisconsin-Madison Scientists have created "atomic scale" memory using individual atoms of Silicon." A cool photo can be found on the site as well.
"An idealist is one who, on noticing that a rose smells better than a cabbage, concludes that it will also make better soup." - H.L. Mencken
Bah! (Score:5, Funny)
Single atom memory? How stable do they REALLY expect that to be?
Ha! What's the name of the technology? Alzheimer's Access Memory?
repost (Score:3, Informative)
http://science.slashdot.org/article.pl?sid=02/08/
Re:repost (Score:2)
Re:repost (Score:1)
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WARNING: Porn (possibly child porn) (Score:1, Offtopic)
what was that.. (Score:2)
And a brick wall?
Methinks there is no higher density than bit-per-atom.
hrm... bit per electron...
Nonsense! (Score:2)
Re:Nonsense! (Score:2)
We can communicate with other universes.
I can transmit messages to Perdos in parallel universes.
No.
You can not store and retrieve more than one bit in an atom using quantum states.
Re:Nonsense! (Score:1)
Damn Quantum computers
Re:what was that.. (Score:2)
Doesnt this assume you can only store information in particles with mass? For instance, light can have wavelengths smaller than the "width" of an electron.
Re:what was that.. (Score:1)
Hint: it's unknown (for the free electron). We only know that the electron is smaller then 10^-15 meters, compare this to the wavelength of visible light: 10^-6 meters. Visible light has HUGE wavelength (several thousand atom spacings)! Guess why we need UV and XUV etc. light for lithography...to get near atom size with light you actually need X-rays!
Re:what was that.. (Score:5, Funny)
And a brick wall?
Methinks there is no higher density than bit-per-atom.
6.02x10^23 Kb ought to be enough for anyone.
What the picture says... (Score:5, Funny)
This has more details (Score:5, Informative)
"Reading the memory consists of a simple, one-dimensional scan, because it is self-formatted into precise tracks. There is no need to search in two dimensions for the location of a bit. The signal is highly predictable since all atoms have the same shape and occur on well-defined lattice sites. That allows for a high level of filtering and error correction"
"Writing is more difficult. While atoms can be positioned controllably at liquid helium temperature, that is much harder to achieve that at room temperature"
Copyright (Score:1)
And it'd be like... (Score:2)
$ solvechess
Please prepare and format 10 Dyson Spheres and fill them with crystalline silicon.
Please insert Dyson Sphere 1 and press enter...
Working..........(10%)
Please insert Dyson Sphere 2 and press enter...
Working...(13%), inf remaining.
Fun, fun, fun. And now we'll put those into a RAID 6+6. How many would you need at least and how many could fail before you lose any data? For bonus points, give the smallest possible distance you could leave between the spheres to keep them separated using no more than the power output of a Sol-like star on each and calculate the mass of all spheres combined. If possible draw a small diagram of how the spheres had to be placed for maximum stability.
Feynman failed to anticipate MS Word (Score:4, Funny)
And then we'd need a new search engine just to find the damn thing.
Fortunately, the text would probably be stored in the innovative MS Word format, which guarantees that the physical size of the required storage capacity will remain constant over time, no matter what the information density of the storage medium.
Re:Feynman failed to anticipate MS Word (Score:1)
Mini-Google, stop humping the laser..
Atom walks into the bar. (Score:4, Funny)
Bartender replies "Are you sure?"
Atom thinks for a second: "Yea I'm positive."
Re:Atom walks into the bar. (Score:1)
Sodium: "Nah. I don't want to be reduced to your level."
Re:Atom walks into the bar. (Score:2)
A neutron walks into a bar and orders a martini. When the bartender hands
him the drink, the neutron asks, "How much do I owe you?"
The bartender replies, "For you
Oops (Score:2)
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FLT (Score:4, Funny)
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Why limit to binary? (Score:1)
Re:Why limit to binary? (Score:2, Interesting)
In addition to requireing extra circuitry for decoding, this would require extra time. If you're wondering why CPUs don't just use various (16/32/64/whatever) voltage levels internally, then you really need a refresher course.
Transistor -> voltage controlled current source. i.e. a transister (in most cpus, these are nmos/pmos pairs) will either be "conducting" or "not conducting" a current depending on voltage level at the gate. Although technically these conducting/non-conducting will have slightly different currents flowing though them, we cannot use these as various voltage levels for the next transister because we get into all sorts of matching problems, fan-in/out problems, and basically (for example) the number "26" would be represented by one voltage level here, a different one there, and another one based on what transisters or conducting, and how much. If you're wondering why we don't use resisters to solve some of these problems, you REALLY need to review - power dicipated = current * current * resistance = heat. 20B currents squared * 20B resistances = instant chip incineration.
As a side note (actually two side notes) I beleive in the 40s they were experimenting with computers which used 10 voltage levels because that was the natuaral thing to do, until someone suggested using binary/boolean value which until that time were just a mathmatical curiosity than a dicipline taken seriously. I don't have references on hand ot back this up, but I think i remember reading something to that effect. The other side note is that many modems (even today) use variable-level voltages ot communicate. This is because the speed limiting factor effecting modems is line quality and length. It takes a relativly long time to force the line to any particular voltage, and so the modem makes these voltages count by encoding multiple levels. Ex. 9600bps modem uses 12 phase angles, four of which have two voltage levels, alowing to transmit 16 bits in one cycle (Stallings, Data & Computer Communications, 6th, p145). This is also why some modems (ex 56k) will only connect at (ex) 24k if excessive line noise prevents reliable encoding on many voltage levels.
The second reason we don't use variable levels in memory storage is error control. 1/0 values are screwed up enough by line noise, magnetic fields, and what have you. Imageine how difficult a time a machine would have dtermining "is that atom 23456 picometers about the base or 23457?"
As photonics emerges as a network technology though, I'm wondering if there is something like a "photo-transister" that will block or allow passthrough of light if light is present at a gate of a certain wavelegth. I know extreamly little about photonics, but if this possible then maybe multiple bits can be transmitted via multiple wavelengths inside a light-based (as opposed to electricity based) processor. Anyonw working on something like this?
Anyway, I hope this helps!
KeggInKenny
Re:Why limit to binary? (Score:1)
9600bps:
12 phase angles, 4 of which have two voltage levels -
8log2 = 3
4log2 * 2 = 4
meaning 9600 sending 7 bits at a time, not 16...
Umm... (Score:2, Interesting)
Re:Umm... (Score:1)
Re:Umm... (Score:1)
Re:Umm... (Score:1)
Re:Umm... (Score:1)
As to the grooves, check this reply in the thread. " This has more details (Score:5, Informative) by jukal " Sorry I don't know how to link directly to the reply.
Mr. Wizard! Mr. Wizard! I have a question please! (Score:1)
I've always wondered that when I see an electron shot like this. Anyone know?
Sorry BoojiBoy0 (Score:1)
Memory Density (Score:1)
Journal article, and some calculations (Score:2, Informative)
In the article they say that their atomic memory has an energy density of 250 terabits per square inch (compared to 100 gigabits per square inch for a hard drive). A CD-ROM has 14 square inches of recordable area. If one were to use this technique on a surface the size of a CD-ROM, that would give:
(14 square inches) * (250 terabits/square inch) / (8 bits/byte) = 437.5 terabytes
Incredibly huge, but I'm sure there's a number of people who would still be able to fill it up.
Obvious silicon quote... (Score:1)
This is what the Awari guys need (Score:2)
(0.778 terabytes) / ((250 terabits/sq.inch) / (8 bits/byte)) = 0.024896 sq.inch =~ 4mm square
Stored at 0K in a vacuum? (Score:2)
CopyRight infringement at atomic level ! (Score:1)
Re:It a hoax... (Score:4, Informative)
Not all atoms are the same size. Remember what you learned about atomic weights?
Re:It a hoax... (Score:3, Informative)
Sizes of atoms. (Score:3, Interesting)
Hydrogen's the smallest, according to my books, with a radius of something like 0.53 angstroms (been a while since I looked it up).
What confuses me is why the atomic radii don't go up as the square of the number of shells. The alkali metals will have a single electron in the outermost shell, with the nucleus shielded by the inner shells, and so having an apparent charge of one. This seems to give a system with size equivalent to the nth energy level of an electron in hydrogen, which goes up as the square of the shell number.
I and the friends I asked about this speculate that because the electrons in the sheilding shells are smeared out radially, the outermost shielding shell extends past the valence shell's nominal radius, and so the core is only partly shielded, but I haven't seen any description to date of how you work out what the radii actually end up being.
Any pointers/quick explanations?
Re:Sizes of atoms. (Score:2)
I'm afraid that, while interesting, this doesn't address my question, which concerned the alkali metals only (as they are presumably the most easily analyzed). I'm just going down a column, not across a row, and finding radii smaller than a naieve model would preduct.
And yes, you are correct: the shielding cannot be perfect. If it were so, the electrons would simply be repelled by one another and not hang out anywhere near the nucleus together anymore.
They still would, as the total charge of the core shells is less than the magnitude of the charge of the nucleus. Even if perfectly spherically distributed and completely inside the valence shell, they'd only cancel as many protons as there are electrons in the non-valence shells.
The (conjectured) reason shielding isn't even this good that a friend and I thougt about was that the second assumption doesn't hold (that the wavefunctions of the inner shells extend past the valence shell, causing some of their charge to not contribute to shielding).
The first assumption should hold, if I understand correctly (the charge distribution of a filled shell has spherical symmetry in the absence of external influences). OTOH, maybe the shells could induce dipoles in each other as with London forces between atoms... Bleah.
Dragging this back to my original question - is there a known, closed-form solution to the radial distribution function for the electrons in alkali metals (or even noble gases), or even a good approximate solution, or am I stuck trying to solve the Schrodinger equation the hard way?
Re:It a hoax... (Score:2)
Re:Okay let me be the first... (Score:1)
Last time i checked same happens to the good old fassioned floopy disk..
I guess the scientist were surprised to find that the atoms stayed where they were left
Exactly. Verry slow at present but being able to keep the atoms where they were put is a step towards a viable atomic storage.
So someone found a way to spend a lot of time using the electron microscope...
Yes electron microscopes have been used to move atoms before. The breakthrough (ignoring the fact it was posted a month ago) is that the self creating tracks and the fact the atoms can be packed at high density and stay there.
On an offtopic side note:
There seems to be an abnormally high number of Trolls on this paticular story. Any ideas why??
Orthanc
Re:Okay let me be the first... (Score:1)
no no, with a floppy disk you just have to stick it in your pocket, 9/10 it will corrupt. Thats why i'm sad enough to duplicate all my files on floppy's and sometimes use 2 different disks. Im sure you could probably duplicate the atomic memory too, it would still be amazing density even at half capacity, even at 1/10 capacity. They can decrease the duplication as the technology for better reliability increases.
Re:Okay let me be the first... (Score:1)
I was refering to the posts not the ratings.