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High-temperature superconductor spills secret: A new phase of matter
PhysOrg ^ | March 24, 2011 | Unknown

Posted on 03/25/2011 3:27:53 PM PDT by decimon

(PhysOrg.com) -- Scientists from the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California at Berkeley have joined with researchers at Stanford University and the SLAC National Accelerator Laboratory to mount a three-pronged attack on one of the most obstinate puzzles in materials sciences: what is the pseudogap?

A collaboration organized by Zhi-Xun Shen, a member of the Stanford Institute for Materials and Energy Science (SIMES) at SLAC and a professor of physics at Stanford University, used three complementary experimental approaches to investigate a single material, the high-temperature superconductor Pb-Bi2201 (lead bismuth strontium lanthanum copper-oxide). Their results are the strongest evidence yet that the pseudogap phase, a mysterious electronic state peculiar to high-temperature superconductors, is not a gradual transition to superconductivity in these materials, as many have long believed. It is in fact a distinct phase of matter.

"This is a paradigm shift in the way we understand high-temperature superconductivity," says Ruihua He, lead author with Makoto Hashimoto of the paper in the March 25 issue of the journal Science that describes the team's findings. "The involvement of an additional phase, once fully understood, might open up new possibilities for achieving superconductivity at even higher temperatures in these materials." When the research was done Hashimoto and He were members of SIMES, of Stanford's Department of Applied Physics, and of Berkeley Lab's Advanced Light Source (ALS), where He is now a postdoctoral fellow.

(Excerpt) Read more at physorg.com ...


TOPICS: Science
KEYWORDS: cooperpairs; jahnteller; jahntellereffect; jahntellermetal; jahntellermetals; stringtheory; superconductivity; superconductor; superconductors
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1 posted on 03/25/2011 3:27:58 PM PDT by decimon
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To: SunkenCiv

Kinetic on pseudogap ping.


2 posted on 03/25/2011 3:29:05 PM PDT by decimon
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To: decimon

My labradoodle eats pseudogaps.


3 posted on 03/25/2011 3:29:34 PM PDT by Drango (NO-vember is payback for April 15th)
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To: decimon

When did lead bismuth strontium lanthanum copper-oxide become a single material?


4 posted on 03/25/2011 3:29:34 PM PDT by Lurker (The avalanche has begun. The pebbles no longer have a vote.)
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To: Lurker
When did lead bismuth strontium lanthanum copper-oxide become a single material?

When the dish ran away with the spoon? Beats me.

5 posted on 03/25/2011 3:33:51 PM PDT by decimon
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To: Lurker

Just another alloy, with interesting electrical properties.


6 posted on 03/25/2011 3:34:29 PM PDT by thackney (life is fragile, handle with prayer (biblein90days.org))
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To: Lurker
When did lead bismuth strontium lanthanum copper-oxide become a single material?

Right after the divorce

7 posted on 03/25/2011 3:34:44 PM PDT by mountainlion (America land of the free because of the Brave.)
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To: decimon

hehe he heh.. heh.. He said ‘kinetic’ heh.. heh.. he hehe.


8 posted on 03/25/2011 3:53:21 PM PDT by DigitalVideoDude (It's amazing what you can accomplish when you don't care who gets the credit. -Ronald Reagan)
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To: Lurker; decimon

Makes sense it would be, I think.

How could it superconduct unless it had all it’s ducks in a row?


9 posted on 03/25/2011 3:57:16 PM PDT by bigheadfred (Beat me, Bite me...Make Me Write Bad Checks)
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To: Lurker

“When did lead bismuth strontium lanthanum copper-oxide become a single material? “

Like yttrium barium copper oxide, (YBa2Cu3O7-x), it is an oxide containing several metal ions. Each one must be given in the name.


10 posted on 03/25/2011 4:31:29 PM PDT by Solidstatechemist (SolidStateChemist)
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To: Lurker

I should have added, yttrium barium copper oxide was the first high temperature superconductor to exhibit superconductivity above the boiling point of liquid nitrogen (T=77K, -196C). It goes superconducting at 93K (-180C).


11 posted on 03/25/2011 4:34:15 PM PDT by Solidstatechemist (SolidStateChemist)
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To: SirKit

Physics Ping!!


12 posted on 03/25/2011 4:47:39 PM PDT by SuziQ
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To: decimon

The key ingredient in the High Tc materials are naturally-ocurring 2-dimensional substrates of CO2.

The High Tc materials are “Jahn-Teller distort materials” - which simply mean that they contain these stable sheets of CO2. Playing around with the other materials changes the hole-doping of the CO2.

Antiferromagnetic exchange between hole-pairs acts as an attractive force between hole pairs on this sort of lattice, but it doesn’t by itself beat charge repulsion.

I left the field before the correct pairing mechanism was identified - if it has indeed yet been identified. The leading theory (IIRC) of the hole-pairing involved not pairing, but collective behaviour due to the fractional quantum Hall effect which can only occur on 2-and-a-bit-dimensional lattices such as these JT-distort lattices.


13 posted on 03/25/2011 5:07:26 PM PDT by agere_contra (As often as I look upon the cross, so often will I forgive with all my heart.)
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To: Solidstatechemist

Do you happen to know what the critical magnetic field is on the YBa2Cu3O7-x family?

What I really want to know is the supportable current density. Does a temp lower than 77K help in this regard?


14 posted on 03/25/2011 5:07:52 PM PDT by Erasmus (I love "The Raven," but then what do I know? I'm just a poetaster.)
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To: Erasmus

IIRC about 100 T. The critical current depends on direction relative to the CUO2 plane.


15 posted on 03/25/2011 5:19:40 PM PDT by agere_contra (As often as I look upon the cross, so often will I forgive with all my heart.)
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To: agere_contra

Ouch, after midnight. Goodnight all.


16 posted on 03/25/2011 5:22:02 PM PDT by agere_contra (As often as I look upon the cross, so often will I forgive with all my heart.)
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To: agere_contra
Critical current, sorry I meant critical magnetic field is directional. Late here.
17 posted on 03/25/2011 5:24:19 PM PDT by agere_contra (As often as I look upon the cross, so often will I forgive with all my heart.)
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To: decimon; AdmSmith; bvw; callisto; ckilmer; dandelion; ganeshpuri89; gobucks; KevinDavis; ...

Thanks decimon.
three complementary experimental approaches to investigate a single material, the high-temperature superconductor Pb-Bi2201 (lead bismuth strontium lanthanum copper-oxide)... are the strongest evidence yet that the pseudogap phase, a mysterious electronic state peculiar to high-temperature superconductors, is not a gradual transition to superconductivity in these materials, as many have long believed. It is in fact a distinct phase of matter.
Pb stands for Pepto-Bismol, and this research isn't done with its investigation of antacids.

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18 posted on 03/25/2011 6:27:13 PM PDT by SunkenCiv (Thanks Cincinna for this link -- http://www.friendsofitamar.org)
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To: decimon
High-temperature superconductor spills secret: A new phase of matter

Solid, Liquid, Gas, Plasma, and Superconductivity?

19 posted on 03/25/2011 6:58:14 PM PDT by Yo-Yo (Is the /sarc tag really necessary?)
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To: agere_contra

That sounds like a whole lotta current density.

But then again, I haven’t had to do that calculation since MetEng 221 (or was it Phys 363?) in 1968.


20 posted on 03/25/2011 9:21:02 PM PDT by Erasmus (I love "The Raven," but then what do I know? I'm just a poetaster.)
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