

Physicists Create a Working Transistor From a Single Atom - dazbradbury
http://www.nytimes.com/2012/02/20/science/physicists-create-a-working-transistor-from-a-single-atom.html

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alecst
Here are some more detailed sources.

[http://www.nature.com/nnano//journal/vaop/ncurrent/pdf/nnano...](http://www.nature.com/nnano//journal/vaop/ncurrent/pdf/nnano.2012.23.pdf)

[http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano...](http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2012.21.html#/acknowledgments)

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andrewcooke
to save people poking around (because the linked article is quite appalling
vague) - what you might call the "active part" of the gate is a single atom.
that is surrounded by input, output, and gate connections and insulation that
are all multiple-atoms in size. so the single, central phosphorous atom
controls the flow from source to drain, depending on the gate voltage.

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archgoon
So it sounds like the challenge at this point is getting sufficiently small
wires.

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da-bacon
Making it work at room temperature is probably a greater long term issue. As
the temperature goes up the system has a higher probability of accessing
states that will make it not function properly (i.e. your logic gates become
probabilistic.)

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NinetyNine
A massive redundant array of probabilistic logic networks sounds pretty
familiar to me.

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bwarp
That's great and all that but you can't scale up production at that scale
(imagine even building an opamp with it) and it doesn't mention anywhere how
long the gate actually lasted. Thermal effects at that scale would probably
destroy it pretty quickly.

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tenpointwo
I think this is more about proof of concept than a presentation of its
readiness for production at a large scale or at any scale. Give it 5 more
years and maybe we'll be closer to seeing it more frequently in the
technologies we use.

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sambeau
Does this say something fundamental about transistors or something fundamental
about atoms?

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ThaddeusQuay2
"Does this say something fundamental about transistors or something
fundamental about atoms?"

Neither. It just says that someone has gotten better at using a hammer to
guide an egg, into a frying pan, without breaking it. And they performed that
trick while wearing thick gloves.

"The central achievement of the latest work is to use the STM–hydrogen-resist
lithography approach to position a single phosphorus atom between source and
drain contacts and two (more distant) gate electrodes."

Also, I take strong issue with the term "single-atom transistor". I would
expect to hear that from a crank working out of his secret basement lab. You
cannot build an electronic device out of a single atom, and obviously, they
used many.

Lastly: "Single-atom transistors represent the ultimate limit in solid-state
device miniaturization." That's patently false. Thousands of atoms were used
here, so there is likely room for improvement.

[http://nature.com/nnano//journal/vaop/ncurrent/pdf/nnano.201...](http://nature.com/nnano//journal/vaop/ncurrent/pdf/nnano.2012.23.pdf)
(Transistors arrive at the atomic limit)(A single-atom transistor has been
made by positioning a phosphorus atom between metallic electrodes, also made
of phosphorus, on a silicon surface)(2012-FEB-19)

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flashingleds
It's an issue of definitions. Of course you cannot build an electronic device
using only a single atom, because you need leads, interconnects, power
supplies, measurement equipment etc. So when you talk about a single atom
transistor, what's meant is that the critical, behaviour determining region of
the device is a single atom. If you took that single atom away, you would not
have a transistor any more.

In much the same way we talk about 32nm transistors in computer chips for
example - it's understood that this number refers to the gate length, not your
whole processor.

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ThaddeusQuay2
"It's an issue of definitions. If you took that single atom away, you would
not have a transistor any more."

No, you would still have a transistor, albeit a non-functioning one, just like
you would still have a car if you removed the engine. I appreciate your effort
to explain, but your explanation is worded for people similar to those who
work in your lab. Definitions should be correct, especially when they are put
forth by the NY Times, a news source for the general public. People have
already had their expectations raised over "jetpacks for everyone any day now"
stories, so it's rather irresponsible to define something new with a name
which is obviously false, and which tends to overrepresent, by far, the
achievement that the name defines. I actually work with nanotech, but the
average reader of the NY Times has little-to-no knowledge of "leads",
"interconnects", "power supplies", "measurement equipment", "critical,
behaviour-determining regions", "gate length", or even: "transistor".

