Re: Thermoelectricity Breakthrough
Uncle Al
>
> Well worth reading.
>
> http://arxiv.org/abs/0906.5391
[snip]
> In summary, we investigated polaron electrodynamics in
> Nb:SrTiO_3/SrTiO_3 superlattices. As the thickness of the Nb:SrTiO_3
> layer in the superlattice decreased, the system experienced a
> dimensional crossover from 3D to quasi-2D. The polaron electrodynamics
> changed significantly due to the dimensional crossover, where the
> polaron effective mass and the relaxation time increased by a factor of
> ~3. We suggest that the Seebeck coefficient could be enhanced due to the
> strong effect of polarons in low dimensional systems. Other oxide
> systems with large electron-phonon coupling should be tested for
> application to future thermoelectric devices.
Theorists boast promiscuity while empiricists pay child support. When
they build a real world device they are credible.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2
Eric Gisse
> Uncle Al wrote:
> > kT wrote:
> >> Well worth reading.
>
> >>http://arxiv.org/abs/0906.5391
> > [snip]
>
> >> In summary, we investigated polaron electrodynamics in
> >> Nb:SrTiO_3/SrTiO_3 superlattices. As the thickness of the Nb:SrTiO_3
> >> layer in the superlattice decreased, the system experienced a
> >> dimensional crossover from 3D to quasi-2D. The polaron electrodynamics
> >> changed significantly due to the dimensional crossover, where the
> >> polaron effective mass and the relaxation time increased by a factor of
> >> ~3. We suggest that the Seebeck coefficient could be enhanced due to the
> >> strong effect of polarons in low dimensional systems. Other oxide
> >> systems with large electron-phonon coupling should be tested for
> >> application to future thermoelectric devices.
>
> > Theorists boast promiscuity while empiricists pay child support. When
> > they build a real world device they are credible.
>
> than no experimental evidence at all, which is where they were before.
>
> Two things of note here : strongly correlated polarons of high effective
> mass, and the dimensional crossover. Once mechanisms of zT enhancement
> are identified, the empirical process of new thermoelectric material and
> structure identification can begin to proceed.
I'll settle for a thermoelectric material that doesn't break down so
quickly so we can have a deep space probe with a 50 year power supply.
BradGuth
> >> Well worth reading.
>
> >>http://arxiv.org/abs/0906.5391
> > [snip]
>
> >> In summary, we investigated polaron electrodynamics in
> >> Nb:SrTiO_3/SrTiO_3 superlattices. As the thickness of the Nb:SrTiO_3
> >> layer in the superlattice decreased, the system experienced a
> >> dimensional crossover from 3D to quasi-2D. The polaron electrodynamics
> >> changed significantly due to the dimensional crossover, where the
> >> polaron effective mass and the relaxation time increased by a factor of
> >> ~3. We suggest that the Seebeck coefficient could be enhanced due to the
> >> strong effect of polarons in low dimensional systems. Other oxide
> >> systems with large electron-phonon coupling should be tested for
> >> application to future thermoelectric devices.
>
> > Theorists boast promiscuity while empiricists pay child support. When
> > they build a real world device they are credible.
>
> than no experimental evidence at all, which is where they were before.
>
> Two things of note here : strongly correlated polarons of high effective
> mass, and the dimensional crossover. Once mechanisms of zT enhancement
> are identified, the empirical process of new thermoelectric material and
> structure identification can begin to proceed.
Uncle Al is always opposed to discovering and/or revising of anything
for the better. It's a Zionist Nazi mindset thing of his.
~ BG
Jon Kirwan
>Uncle Al wrote:
>> kT wrote:
>>> Well worth reading.
>>>
>>> http://arxiv.org/abs/0906.5391
>> [snip]
>>
>>> In summary, we investigated polaron electrodynamics in
>>> Nb:SrTiO_3/SrTiO_3 superlattices. As the thickness of the Nb:SrTiO_3
>>> layer in the superlattice decreased, the system experienced a
>>> dimensional crossover from 3D to quasi-2D. The polaron electrodynamics
>>> changed significantly due to the dimensional crossover, where the
>>> polaron effective mass and the relaxation time increased by a factor of
>>> ~3. We suggest that the Seebeck coefficient could be enhanced due to the
>>> strong effect of polarons in low dimensional systems. Other oxide
>>> systems with large electron-phonon coupling should be tested for
>>> application to future thermoelectric devices.
>>
>> Theorists boast promiscuity while empiricists pay child support. When
>> they build a real world device they are credible.
>
>Well Al, some experimental evidence via optical spectroscopy is better
>than no experimental evidence at all, which is where they were before.
>
>Two things of note here : strongly correlated polarons of high effective
>mass, and the dimensional crossover. Once mechanisms of zT enhancement
>are identified, the empirical process of new thermoelectric material and
>structure identification can begin to proceed.
I read over it. I'll make one admittedly ignorant comment.
>><snip of earlier post>
>>and tau increases. Therefore, this intriguing behavior of tau also
>>confirms the polaron picture in our Nb:STO/STO SLs (superlattices).
>><snip>
This change in tau (lengthening) has the "gut feel" to me of unfavored
(illegal) quantum state transitions. Like singlet/triplets? Their
chain of reasoning does seem just a bit stretched, as written, and I
wasn't convinced that their suggestion was necessarily the right one.
I need to read a lot more about polaron theory, though.
Jon
Uncle Al
>
> Uncle Al wrote:
> > kT wrote:
> >> Well worth reading.
> >>
> >> http://arxiv.org/abs/0906.5391
> > [snip]
> >
> >> In summary, we investigated polaron electrodynamics in
> >> Nb:SrTiO_3/SrTiO_3 superlattices. As the thickness of the Nb:SrTiO_3
> >> layer in the superlattice decreased, the system experienced a
> >> dimensional crossover from 3D to quasi-2D. The polaron electrodynamics
> >> changed significantly due to the dimensional crossover, where the
> >> polaron effective mass and the relaxation time increased by a factor of
> >> ~3. We suggest that the Seebeck coefficient could be enhanced due to the
> >> strong effect of polarons in low dimensional systems. Other oxide
> >> systems with large electron-phonon coupling should be tested for
> >> application to future thermoelectric devices.
> >
> > Theorists boast promiscuity while empiricists pay child support. When
> > they build a real world device they are credible.
>
> than no experimental evidence at all, which is where they were before.
>
> Two things of note here : strongly correlated polarons of high effective
> mass, and the dimensional crossover. Once mechanisms of zT enhancement
> are identified, the empirical process of new thermoelectric material and
> structure identification can begin to proceed.
They have a basic research project. It is not applied research nor is
it technology. Some idiot decided scientists must walk the street
like hookers, showing a little pussy to get funded. It is
disingenuous and professionally offensive. This is empirically
unnecessary for Welfare and Medicaid. "GIMME!"
The State of California this morning, 01 July, declared financial
illiquidity. Welfare Friday will be State IOUs that "should be
honored by banks." Welfare requires you have no bank account or other
liquid assets. No bank will cash non-depositor financial instruments
without a fee - if at all. Banks are not bound by any law to
cooperate, nor can they justify cashing unsecured fiat notes.
04 July fireworks? Uncle Al is a reasonable man. (Everybody knows
the remainder of the quotation - or will learn at 1325 fps.)
BradGuth
> (Toxic URL! Unsafe for children and most mammals)http://www.mazepath.com/uncleal/lajos.htm#a2
Disingenuous and professionally offensive, just like yourself (aka Mr.
Naysay), so you should know better than anyone else.
~ BG
Jon Kirwan
>Good luck with that, I burned through a lot of papers in the early 90's.
I think I'd like to start with Feynman's path-integral approach -- at
least I've some familiarity with quantum action and varying phase over
paths so I wouldn't be completely blind-sided. Any suggestions?
>It's pretty simplistic reasoning for polaron theory, which is a well
>developed macroscopic theory, but has a long way to go microscopically.
That's what it looked like, to me... a macroscopic model that allows
some predictive facility without necessarily saying that is exactly
what is going on underneath. Like phonons.
>Plus there are all kinds of (bi)polarons in every size, mass, etc.
I saw that. Made me wonder if bipolarons treated as bosonic instead
of fermionic.
>Spectroscopy is the right way to approach this problem, though.
I'm with you, there.
>Fundamentally, composite quasi-particles are dressed with all sorts of
>other lower energy excitations induced by strong electronic correlations
>and ultimately causing complete localization, nanoscopic and finally
>macroscopic phase separation. Throw in a quantum critical point - voila!
Okay. There is where I need to see the theory so that I can deduce
these cases from it. Which gets me back to square 1, above. Any
recommendations before I get come to my senses enough to realize how
much wasted effort this is going to take and how little I'll get from
it?
Jon
Uncle Al
Hey stooopid - if you can't get jiggy with empirical observation, if
you can't take the heat for not being so, get out of Hell.
What happened to the Mars face, Guth?
What happened to the rocket powered by an extension cord, Guth?
idiot
--
Uncle Al
Jon Kirwan
>Sorry, can't help you, it's an extremely broad field that ARPES and
>other spectroscopies is totally revolutionizing. I can't believe how
>primitive the early polaron work was, Mott won a Nobel prize with it.
Hmm. But primitive is where I need to start. Just as understanding
the mathematics of fluids and heat transfer were an important segue
into following just how and why Faraday postulated EM�s fluid-like
character. Or that understanding Hamilton's kinetics principle is an
important segue into grasping the hows and whys of Schr�dinger's wave
equation. Things build on other things. I'd rather not just jump
into the deep end!
I guess I can't get a greased slide from you, then.
>>> It's pretty simplistic reasoning for polaron theory, which is a well
>>> developed macroscopic theory, but has a long way to go microscopically.
>>
>> That's what it looked like, to me... a macroscopic model that allows
>> some predictive facility without necessarily saying that is exactly
>> what is going on underneath. Like phonons.
>>
>>> Plus there are all kinds of (bi)polarons in every size, mass, etc.
>>
>> I saw that. Made me wonder if bipolarons treated as bosonic instead
>> of fermionic.
>
>You need to read anything recent by Philip Phillips, there are composite
>bosons we don't even know about : Mottness - I guess you could call them
>Mottons. The high energy spectral weight from the upper Hubbard band is
>sent clear across the gap where it hooks up with low energy doped hole.
>
>http://arxiv.org/find/cond-mat/1/au:+Phillips_P/0/1/0/all/0/1
>
>That would be an extreme case of strong correlation.
>
>The British emeritus chemist John J. Wilson is worth reading as well :
>
>http://arxiv.org/find/cond-mat/1/au:+Wilson_J/0/1/0/all/0/1
Deep-end of the pool? I guess I can go look.
>>> Spectroscopy is the right way to approach this problem, though.
>>
>> I'm with you, there.
>
>A lot of the original workers died, a modern group would be Fehske et al.
>
>http://arxiv.org/find/cond-mat/1/au:+Fehske_H/0/1/0/all/0/1
Thanks.
>>> Fundamentally, composite quasi-particles are dressed with all sorts of
>>> other lower energy excitations induced by strong electronic correlations
>>> and ultimately causing complete localization, nanoscopic and finally
>>> macroscopic phase separation. Throw in a quantum critical point - voila!
>>
>> Okay. There is where I need to see the theory so that I can deduce
>> these cases from it. Which gets me back to square 1, above. Any
>> recommendations before I get come to my senses enough to realize how
>> much wasted effort this is going to take and how little I'll get from
>> it?
>
>It's fun! At the very least you should be a crackpot idea out of it.
>
>That will tie you up for years. Trust me.
I've got enough that I already need a longer lifetime than I've
actually got. ;)
Jon
BradGuth
We see that you've got yourself yet another blocked fart. You really
should have that looked at before you explode and then implode from
the vacuum created.
~ BG