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A visualization of the molecule. The triangular depression on the bottom right represents the arsenic atom. The dots in the center saucer are bonding locations for a single electron. The yellow dots in the upper left center are bonding locations in which the electron is in a quantum state.  (Source: Purdue University image/David Ebert)
Nanoelectronics researchers discover a bizarre shaped molecule in one of their devices can act as first known quantum state-manipulable atom

Imagine a tiny arsenic atom embedded in a tiny strip of silicon atoms.  An electric current is applied.  Something strange arises on the surface -- an exotic molecule.  On one end is the spherical submerged arsenic atom; on the other end is an "artificial" flat atom, seemingly 2D, created as an artifact.  The pair form an exotic molecule, which has a shared electron, which can be manipulated to be at either end, or in an intermediate quantum state.

Thus arose one of the most confusing, most promising, and strangest breakthroughs in the newly formed field of quantum computing. 

Quantum computing is the term referring to a unique type of computing that takes advantage of physics phenomena on a very small subatomic scale.  Whereas a traditional computer works in bits -- 1s and 0s, which represent the presence or absence of groups of electrons -- a quantum computer use qubits -- multi-state units based on the position and characteristics of a single electron.  A single qubit can encode far more information leading to faster, smaller computers.

Imagine a census computer.  In a modern computer, information would be stored across trillions of bits, encoding the person's name, address, and status.  In a quantum computer this same information could be stored across a much smaller handful of bits.  The computer could "see" multiple people's information simultaneously, allowing for instant processing of vast amounts of data and easier searches.

Further quantum computing looks to exploit other unusual physical phenomena such as entanglement, which allows two atoms at a distance to instantly communicate.  Such communication could be faster than light without violating relativity.

In order to construct a full quantum computer, you must have an atom or molecule capable of containing multiple quantum states.  Formerly, such a manipulable molecule remained undiscovered, but with the discovery of the exotic compound, quantum computing hopes are invigorated.

Gerhard Klimeck, professor of electrical and computer engineering at Purdue University and associate director for technology for the national Network for Computational Nanotechnology remarked, "Up to now large-scale quantum computing has been a dream.  This development may not bring us a quantum computer 10 years faster, but our dreams about these machines are now more realistic."

He continued, "If you want to build a quantum computer you have to be able to control the occupancy of the quantum states.  We can control the location of the electron in this artificial atom and, therefore, control the quantum state with an externally applied electrical field."

The new molecule was first discovered by Sven Rogge and his colleagues at Delft University of Technology in the Netherlands.  His team was experimenting on impurities in nano-scale transistors.  They found that a single atom was transporting electrons, but could not find the impurity responsible.  It turned out it was not an impurity, but a synthetic atom with an unknown proton/neutron character, created by the electrical current.  The exotic atom was flat and formed a molecule with an arsenic atom on the transistor.

Much of this picture only became clear thanks to the work of physicist Lloyd Hollenberg and colleagues at the University of Melbourne in Australia who helped to explain the molecule's strange behavior and appearance.

Hollenberg explained, "The team found that the measurements only made sense if the molecule was considered to be made of two parts.  One end comprised the arsenic atom embedded in the silicon, while the 'artificial' end of the molecule forms near the silicon surface of the transistor. A single electron was spread across both ends.  What is strange about the 'surface' end of the molecule is that it occurs as an artifact when we apply electrical current across the transistor and hence can be considered 'manmade.' We have no equivalent form existing naturally in the world around us."

Klimeck, and graduate student Rajib Rahman used the analysis to develop a three million-atom model in nano-electronics modeling program NEMO 3-D to analyze the behavior.  From this, they determined that the exotic flat atom represented a controllable quantum state atom, via its electron.  The quantum state was voltage dependent, the necessary characteristic for an electricity-based quantum computer.

Last David Ebert, a professor of electrical and computer engineering at Purdue, and graduate student Insoo Woo, helped transform the model into an image to help visualize the discovery.

Delft's Rogge, the first of the discoverers stated, "Our experiment made us realize that industrial electronic devices have now reached the level where we can study and manipulate the state of a single atom.  This is the ultimate limit, you cannot get smaller than that."

The breakthrough, like many historic ones (such as the discovery of Penicillin), was largely accidental.  And it is extremely fortunate, in that it may one day allow complex, incredibly powerful quantum computers to become reality and solve many complex sets of problems.



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atom?
By drank12quartsstrohsbeer on 7/2/2008 12:23:22 PM , Rating: 3
I thought arsenic was a molecule.




RE: atom?
By masher2 (blog) on 7/2/2008 12:31:36 PM , Rating: 2
It's an element, which means it can be present in atomic or molecular form.


RE: atom?
By geddarkstorm on 7/2/2008 12:56:30 PM , Rating: 3
Oiy, arsenic is an atom. When it forms a bond with another atom, that makes a molecule. Molecule is two or more bonded atoms. In this discussion, the arsenic formed a bond with a fake, induced "atom", which was an artifact created by electron flow through the semi-conductor; thus making a "manmade" molecule.


RE: atom?
By masher2 (blog) on 7/2/2008 3:52:14 PM , Rating: 2
> "Oiy, arsenic is an atom."

Oiy, if you find a piece of pure arsenic, it will be in molecular form, just as you'll find hydrogen, oxygen, carbon, and most other elements. Nature abhors an unbonded atom.


RE: atom?
By DeepBlue1975 on 7/2/2008 7:35:33 PM , Rating: 2
Specially if the atom is in gaseous form.


RE: atom?
By biotech on 7/2/2008 8:11:09 PM , Rating: 2
Not entirely true! Elemental gases exists as molecules, for example Hydrogen, Oxygen, Chlorine, etc. etc. Which is the reason we write them as H2, O2 and Cl2. The Valence Electron Shell Pair Repulsion Theory explains most of this.

Most pure metals on the other hand exist in the atomic and not molecular state including arsenic. If you would heat a metal to a gaseous state it will be molecular. Pure solid elemental metals are atomic and not molecular.


RE: atom?
By masher2 (blog) on 7/2/2008 10:52:30 PM , Rating: 2
> "Most pure metals on the other hand exist in the atomic and not molecular state including arsenic."

You forget arsenic has many allotropes. Yellow arsenic -- which is about the only pure arsenic you're likely to find in nature -- is As4, which is, of course, the molecular form. The metalloid forms are atomic.


RE: atom?
By Torres9 on 7/5/2008 1:17:21 AM , Rating: 1
erm.... just thought to mention group VIII on the periodic table.. you know... the inert/noble gases.. that have a full valence shell and thus don't bond well... maybe you should make sure you don't discriminate against such "noble" gases :P... get your facts straight!!
just to name a few of them :D:D
argon, radon, xenon, neon, krypton, AND HELIUM
I'm not saying they don't bond... i'm just saying there are atoms out there that are unbonded
http://en.wikipedia.org/wiki/Noble_gas
http://en.wikipedia.org/wiki/Noble_gas_compound


RE: atom?
By masher2 (blog) on 7/6/2008 6:58:33 PM , Rating: 2
Which is why I stated "most" elements.


RE: atom?
By drank12quartsstrohsbeer on 7/2/2008 5:37:59 PM , Rating: 3
oops, you are correct. I was thinking of cyanide -- got my poisons mixed up.


RE: atom?
By masher2 (blog) on 7/2/2008 7:05:03 PM , Rating: 5
Remind me to not eat dinner at your house anytime soon.


RE: atom?
By wordsworm on 7/3/2008 10:47:13 AM , Rating: 2
quote:
Remind me to not eat dinner at your house anytime soon.


You deserve a plussy for that one. But, seriously, is one poison worse than the other? Or do you figure it rude to be poisoned by cyanide when you were expecting arsenic seasoning?


RE: atom?
By sinful on 7/3/2008 7:16:25 PM , Rating: 2
Cyanide tastes like almonds.
Maybe some people don't like almond flavor poison.
;)


By jv0704 on 7/3/2008 7:18:05 AM , Rating: 2
im not sure if this is any related to this post but after reading the thread, i was a bit intrigued by the discussion of the big bang theory and had a little say.

firstly, when i think about big bang, the first question to me is, why was there a big bang in the first place?

which then leads to questions like, what are we doing here?

i'm not a scientists of any sort, i'm just a programmer who try to get by life who have a wife and a daughter. but i am fascinated by this world and i just can't help to think but to question myself, 'finding the meaning behind the purpose of big bang'.

i don't know why scientists work so hard to understand the theory behind big bang. it seems a bit dubious that they try to find out what happened at the moment big bang occurred instead of trying to understand what could have happened before it/or triggered it.

can we use this world as the basis of fact for scientists to study that God exists? possibly open up a new venue for scientists to look into?

because it seems like scientists are so concerned about no facts in God when i think the facts are staring right at them.

i may be scolded for saying this but, i think we really have to give credit to this old saying, 'And God said let there be light'. i'm not sure if any scientific theories can top this one. because at the end, some 'thing' had to create the light.

i'm not here to make any judgement or be biased to who is right or wrong.

i'm just stating my feelings when it comes to science and religion. i just can't help to wonder what type of advancements we would make when we combine science and religion to one?

- JV




By Aloonatic on 7/3/2008 8:48:39 AM , Rating: 3
I think you are kinda talking about a branch of creationism called "intelligent design"?

http://en.wikipedia.org/wiki/Intelligent_design

I think science just examines what is available and tries to understand it, there's no real goal or focus other than to further understanding, though it invariably goes where the money is too of course, but not always.

Now if you're Christian, you'll know that God doesn't like people trying to gain knowledge especially when it is comes in apple form, apparently. :)

When you're talking about the bigger questions, scientists just go where their discoveries take them, and maybe through trying to understand the Big Bang they mite prove that God does exist?

Then I guess when God holds his/her/its hands up and says "you've found me" they mite then shed a little light on who/what made god and what came before them and so on.....

Thinking that a scientist cannot believe in god is a mistake that many people make, there's no reason why that should be the case and I'm sure that many do.


By Yossarian22 on 7/5/2008 12:39:08 AM , Rating: 2
quote:
i may be scolded for saying this but, i think we really have to give credit to this old saying, 'And God said let there be light'. i'm not sure if any scientific theories can top this one. because at the end, some 'thing' had to create the light.

And then something had to create that thing. And something had to create that something ad infinitum.

Saying "God did it" or "It just happens" are both entirely useless responses to how the universe came into being. If anything, the problem of a first cause points more towards a flaw in our notion of causality than anything else.