Scientists discover world's smallest superconductor

Mar 29, 2010
This image shows several nanoscale superconducting molecular wires on a silver substrate. Credit: Image courtesy of Saw‑Wai Hla and Kendal Clark, Ohio University.

Scientists have discovered the world's smallest superconductor, a sheet of four pairs of molecules less than one nanometer wide. The Ohio University-led study, published Sunday as an advance online publication in the journal Nature Nanotechnology, provides the first evidence that nanoscale molecular superconducting wires can be fabricated, which could be used for nanoscale electronic devices and energy applications.

"Researchers have said that it's almost impossible to make nanoscale interconnects using metallic conductors because the resistance increases as the size of wire becomes smaller. The become so hot that they can melt and destruct. That issue, Joule heating, has been a major barrier for making a reality," said lead author Saw-Wai Hla, an associate professor of physics and astronomy with Ohio University's Nanoscale and Institute.

Superconducting materials have an electrical resistance of zero, and so can carry large electrical currents without power dissipation or heat generation. Superconductivity was first discovered in 1911, and until recently, was considered a macroscopic phenomenon. The current finding suggests, however, that it exists at the molecular scale, which opens up a novel route for studying this phenomenon, Hla said. Superconductors currently are used in applications ranging from supercomputers to brain imaging devices.

This image shows the smallest superconductor, which is only .87 nanometer wide. Credit: Image courtesy of Saw‑Wai Hla and Kendal Clark, Ohio University.

In the new study, which was funded by the U.S. Department of Energy, Hla's team examined synthesized molecules of a type of organic salt, (BETS)2-GaCl4, placed on a surface of silver. Using scanning tunneling spectroscopy, the scientists observed superconductivity in molecular chains of various lengths. For chains below 50 nanometers in length, superconductivity decreased as the chains became shorter. However, the researchers were still able to observe the phenomenon in chains as small as four pairs of molecules, or 3.5 nanometers in length.

To observe at this scale, the scientists needed to cool the molecules to a temperature of 10 Kelvin. Warmer temperatures reduced the activity. In future studies, scientists can test different types of materials that might be able to form nanoscale superconducting wires at higher temperatures, Hla said.

"But we've opened up a new way to understand this phenomenon, which could lead to new materials that could be engineered to work at higher temperatures," he said.

The study also is noteworthy for providing evidence that superconducting organic salts can grow on a substrate material.

"This is also vital if one wants to fabricate nanoscale electronic circuits using organic molecules," Hla added.

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labtvonline
2.7 / 5 (3) Mar 29, 2010
It seems like every time I turn around that a new groundbreaking revelation has occurred thanks to nanotechnology! I feel that there is amazing promise in the field of nanotech because of the efficiency and endless possibilities. Scientists are just beginning to understand how the physics even work on a nano level. I just saw how the military designed a solar panel that is flexible and 10,000 times more efficient the the old standard cell. I'll post a link if you want to see it for yourself. I feel like in the next five years, nanotechnology will be the technology behind every great invention and breakthrough of the future!

http://www.ndep.u...;t=It's a Small World
jonnyboy
2 / 5 (2) Mar 29, 2010
I watched the webisode and just because the Lieutenant says it, doesn't make it true. Since current solar cells are around 6% efficient then 10,000 times more efficient would make them put out 600 times more power than they absorb .......... clearly false. I think that he must have been referring to an increase in efficiency in the materials that he was holding in his hands not comparing that material to current solar cells.
jimbo92107
4 / 5 (1) Mar 29, 2010
Maybe this is how a room temperature superconductor will be found: Between two electrodes researchers will literally nudge molecules around until the measured resistance drops to zero.
fixer
3 / 5 (1) Mar 29, 2010
Quite entertaining video, but seeing the "technician" using a kitchen fork to shift samples is a mite suspicious.
I agree that the 10,000 x is tripe! double the efficiency would be sensational.
Still, the idea is good.
Flexible cells of any efficiency would be cheap and light and so much more appealing to the consumer.
johanfprins
1 / 5 (2) Mar 30, 2010
Maybe this is how a room temperature superconductor will be found: Between two electrodes researchers will literally nudge molecules around until the measured resistance drops to zero.

It has already been done by myself; but is blocked from being published by the mainstream "experts" on superconduction since it proves that superconduction has NOTHING to do with electrons forming pairs.
This is an astonishing story about the demise of physics which will soon be exposed in my upcoming book "The Physics Delusion". Suffice to note that all the models for which Nobel Prizes have been awarded are plain claptrap. So are the Nobel Prizes for quantum field theory based on the same concepts like Nambu's "spontaneous symmetry breaking".
Jayman
3 / 5 (1) Mar 30, 2010
I have been following superconductivity for over 30 years now and the promise of room-temperature superconductivity is just that - a promise. I tend to get very skeptical at the mere mention of the world. After cold fusion, that is.
FastEddy
not rated yet Mar 30, 2010
Back to the subject article:

" ... For chains below 50 nanometers in length, superconductivity decreased as the chains became shorter. ..." !! ?? !!

Some interesting phenomena going on here, for sure. Still a long way from "room temp", but as an indicator of a future tech ...

" ... "This is also vital if one wants to fabricate nanoscale electronic circuits using organic molecules," Hla added."

Meaning I would guess, some sort of complex carbon (graphene or Buckey type?) as substrate? Maybe some Silver/Carbon/Other complex?

I say, keep the faith and keep looking forward past this possible milestone marker.

(My opinion is that there isn't enough Bismuth on the planet for that path to be of much use as a macro scale SC. Maybe Boron coatings on Carbon complex and/or Silver?)
FastEddy
not rated yet Mar 30, 2010
Jayman: " ... the promise of room-temperature superconductivity is just that - a promise. ..."

Well, yes, right now you are correct. I'm sure you have seen what's going on with Carbon (Graphene, et al) ... Getting closer to room temp "super" conducting = very short pathways of Graphene indicate very, very good conduction, very, very low resistance ... Which if it can be scaled up, will do nicely until genuine "super conducting" comes along. Considering that practical, operational power "wire" resistances dropping 20% below that of pure Silver would save 100, mile long, coal trains per year on the secondary 600-2400 volt grid. "Super" might be too much to ask ... Almost "perfect" or very, very good may be enough to green up the grid quite a bit.
johanfprins
1 / 5 (1) Mar 30, 2010
I have been following superconductivity for over 30 years now and the promise of room-temperature superconductivity is just that - a promise. I tend to get very skeptical at the mere mention of the world. After cold fusion, that is.

You might have followed it but have not been able to understand the fact that the London bros., Bardeen, Cooper, Schrieffer, Landau, Ginsberg, Abrikosov, Josephson, Pippard etc. did not know Atha from Matha. Once you understand the simple fact that a superconductor must cancel an applied electric field by polarisation, it is easy to obtain superconduction at room temperature as I have already done nearly 10 years ago.
taka
not rated yet Mar 31, 2010
To cancel an applied electric field by polarization is necessary, but it seems that it is not enough. Then there are no more free electrons that can scatter from impacting atoms and generate heat and resistance this way, but even tunnelling between stationary allocations will shake atoms and so generate heat and this mean also resistance. This shaking must also be suppressed, and it seems that it is suppressed by quantifying atoms movements (phonons) so that they cannot get more energy from electrons.
(johanfprins successful experiment work with electrons that were forced out from substrate, so shaking was not a problem there)
johanfprins
1 / 5 (1) Apr 01, 2010
To cancel an applied electric field by polarization is necessary, but it seems that it is not enough. Then there are no more free electrons that can scatter .... but even tunnelling between stationary allocations will shake atoms and so generate heat and this mean also resistance.

Not when tunnelling is driven by quantum fluctuations: A carrier can then borrow energy (del)E for a time (del)t to jump from one site to the next: This is made possible by Heisenberg's uncertainty relationship. Before jumping there is no energy to dissipate and after jumping there is alo no energy to dissipate. This also satisfies the second law of thermodynamics according to which non-ending movement can only occur when energy is used to do work and this energy is then returned en-toto to again being used.
Coper pairs cannot do the latter and can thus not explain superconduction. Furthermore when doing the analysis in terms of quantum fluctuations it is found that the carriers are singly-charged.
taka
not rated yet Apr 01, 2010
All tunnelling is driven by quantum fluctuations, this is the definition of it. But I am surprised that you use uncertainty for description, it should not agree with your claim that there is no uncertainty, there is only wave density/intensity that matters. I believe the same equation can be interpreted in these terms also, the uncertainty become particle size then. Like - there is not enough energy to move whole electron throw, but some part of it can be still moved, if this part is over it return the energy to the rest that can now follow.

I found interesting material that clam that this Heisenberg fundamental equation was not a probability but an actuality (http://www.wbabin...15.pdf).

Matter shaking happen not because of electrons kinetic energy, but as when electron is on one position it drags atoms and so the material deform. When it is on next position it drags atoms differently and material deform differently. The result is shaking.
johanfprins
1 / 5 (1) Apr 01, 2010
All tunnelling is driven by quantum fluctuations, this is the definition of it...

Just like "uncertainty" the term "tunnelling" should be banned. An electron-wave cannot move THROUGH an energy barrier, it can only scale an energy barrier. Heisenberg's relationship (leave the misleading term "uncertainty" out since there is no "uncertainty" involved) for energy and time allows an electron wave to borrow energy (del)E as long as it is not for longer than (del)t. This allows a charge carrier to jump OVER a barrier: Such a loan of energy actually defines a quantum fluctuation; not the probabilistic movement of a particle as is propagated in the literature based on te Copenhagen BS. The so called "uncertainties are the average sizes of the wave-intensity in space-time and its reciprocal space-time.
In a SC, the phase is in a ground-state so that energy cannot dissipate during the jump from one site to the other: No "shaking" which can cause energy loss is at all possible.
localcooling
not rated yet Apr 04, 2010
I wonder how "low temperature spaces" behave at nano-levels? Is it possible to thermally insulate a nano-wire with a nano-insulating sheet ??? I'm at a loss as how temperature, insulation etc. etc. works at a nano-scale. Can anyone inform me ?

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