Re: [Vo]:A Super New Theory to Explain Superconductivity

[Bob Higgins]

When I worked in research for a large company, the discovery of the first
HTSCs stimulated research into the RF properties of superconductors - type
I and type II.  Since there was a huge jump in Tc, we considered that room
temperature superconductors were just around the corner.  What we
discovered was that the higher the Tc, the worse the usable qualities of
the superconductor.  Our estimate was that a RTSC would actually be no
better than copper.  Superconductors are only zero resistance at DC.  There
is a finite penetration of current in all superconductors for AC and RF.
 The closer you are to the Tc and the higher the Tc is, the more AC/RF
resistance you have and the lower the critical magnetic field.  Our
conclusion was that the only superconductors that were useful over Cu for
RF applications were deeply cooled Type I.  I think that RTSCs will only
have niche applications.  But ... I would love to be surprised.

On Sun, Jul 11, 2021 at 3:02 PM Jones Beene  wrote:

> Well as this paper implies, the field of superconductivity is "heating up"
> these days ..literally
>
> The prior story which may be very important on this point - and in the
> relentless progress towards usable RTSC - room temperature
> superconductivity - itself came out just a few weeks back
>
>
> https://phys.org/news/2021-07-ternary-hydrides-lanthanum-yttrium-high-temperature.html
> '
>
> ...  which is a high pressure but ambient temp (non cryogenic)
> phenomenon... involving superhydrides ... which curiously could be related
> to LENR and the Mills/Holmlid effect, if as I suspect the superhydrides are
> found to be in highly redundant ground states (as an alternative to
> pressurization)
>
> The holy grail of course would be a metal superhydride going into RTSC phase
> at ambient pressure.
>
> This advance would revolutionized the economy in so may ways - it would be
> the "next big thing" as they say.
>
> Does the "Berry phase" of this new theory help us to understand
> superhydride RTSC ?
>
> It doesn't look that way so far. The whole thing could be little more than
> hype if it does not illuminate RTSC.
>
> You have to worry when a PR firm releases a technical paper.
>
>
>  Kevin O'Malley wrote:
>
>
> *A Super New Theory to Explain Superconductivity*
> 
> *Journal of Superconductivity and Novel Magnetism ^
>  *|
> 5 July 2021 | Hiroyasu Koizumi
>
>

Re: [Vo]:A Super New Theory to Explain Superconductivity

[Jones Beene]

 Well as this paper implies, the field of superconductivity is "heating up" 
these days ..literally
The prior story which may be very important on this point - and in the 
relentless progress towards usable RTSC - room temperature superconductivity - 
itself came out just a few weeks back

https://phys.org/news/2021-07-ternary-hydrides-lanthanum-yttrium-high-temperature.html'
...  which is a high pressure but ambient temp (non cryogenic) phenomenon... 
involving superhydrides ... which curiously could be related to LENR and the 
Mills/Holmlid effect, if as I suspect the superhydrides are found to be in 
highly redundant ground states (as an alternative to pressurization)

The holy grail of course would be a metal superhydride going into RTSC phase at 
ambient pressure. 

This advance would revolutionized the economy in so may ways - it would be the 
"next big thing" as they say. 

Does the "Berry phase" of this new theory help us to understand superhydride 
RTSC ? 

It doesn't look that way so far. The whole thing could be little more than hype 
if it does not illuminate RTSC.
You have to worry when a PR firm releases a technical paper.


    Kevin O'Malley wrote:  
 
 A Super New Theory to Explain Superconductivity
Journal of Superconductivity and Novel Magnetism ^ | 5 July 2021 | Hiroyasu 
Koizumi

  

[Vo]:A Super New Theory to Explain Superconductivity

[Kevin O'Malley]

*A Super New Theory to Explain Superconductivity*

*Journal of Superconductivity and Novel Magnetism ^
 *|
5 July 2021 | Hiroyasu Koizumi

Posted on *7/11/2021, 7:26:10 AM*

A Super New Theory to Explain Superconductivity

By UNIVERSITY OF TSUKUBA JULY 10, 2021

Electricity Superconductivity Concept

A researcher at the University of Tsukuba introduces a new theoretical
model of high-temperature superconductivity, in which electrical current
can flow with zero resistance, which may lead to extremely efficient energy
generation and transmission.

A scientist from the Division of Quantum Condensed Matter Physics at the
University of Tsukuba has formulated a new theory of superconductivity.
Based on the calculation of the “Berry connection,” this model helps
explain new experimental results better than the current theory. The work
may allow future electrical grids to send energy without losses.

Superconductors are fascinating materials that may look unremarkable at
ambient conditions, but when cooled to very low temperatures, allow
electrical current to flow with zero resistance. There are several obvious
applications of superconductivity, such as lossless energy transmission,
but the physics underlying this process is still not clearly understood.
The established way of thinking about the transition from normal to
superconducting is called the Bardeen-Cooper-Schrieffer (BCS) theory. In
this model, as long as thermal excitations are kept small enough, particles
can form “Cooper pairs” which travel together and resist scattering.
However, the BCS model does not adequately explain all types of
superconductors, which limits our ability to create more robust
superconducting materials that work at room temperature.

Now, a scientist from the University of Tsukuba has come up with a new
model for superconductivity that better reveals the physical principles.
Instead of focusing on the pairing of charged particles, this new theory
uses the mathematical tool called the “Berry connection.” This value
computes a twisting of space where electrons travel. “In the standard BCS
theory, the origin of superconductivity is electron pairing. In this
theory, the supercurrent is identified as the dissipationless flow of the
paired electrons, while single electrons still experience resistance,”
Author Professor Hiroyasu Koizumi says.

As an illustration, Josephson junctions are formed when two superconductor
layers are separated by a thin barrier made of normal metal or an
insulator. Although widely used in high-precision magnetic field detectors
and quantum computers, Josephson junctions also do not fit neatly the
inside BCS theory. “In the new theory, the role of the electron pairing is
to stabilize the Berry connection, as opposed to being the cause of
superconductivity by itself, and the supercurrent is the flow of single and
paired electrons generated due to the twisting of the space where electrons
travel caused by the Berry connection,” Professor Koizumi says. Thus, this
research may lead to advancements in quantum computing as well as energy
conservation.

Reference: “Superconductivity by Berry Connection from Many-body Wave
Functions: Revisit to Andreev−Saint-James Reflection and Josephson Effect”
by Hiroyasu Koizumi, 5 July 2021, Journal of Superconductivity and Novel
Magnetism. DOI: 10.1007/s10948-021-05905-y
-
arXiv.org > cond-mat > arXiv:2105.02364

https://arxiv.org/abs/2105.02364

Condensed Matter ~~ Superconductivity [Submitted on 5 May 2021] Berry
connection from many-body wave functions and superconductivity:
Calculations by the particle number conserving Bogoliubov-de Gennes
equations

Hiroyasu Koizumi, Alto Ishikawa A fundamentally revised version of
superconductivity theory has been put forward by the present authors since
the standard theory of superconductivity based on the BCS theory cannot
explain superconductivity in cuprates discovered in 1986, and
reexaminations on several experimental results on the conventional
superconductors indicate the necessity for a fundamental revision.

The revision is made on the origin of the superconducting phase variable,
which is attributed to a Berry connection arising from many-body wave
functions. With this revision, the theory can be cast into a particle
number conserving formalism. We have developed a method to calculate
superconducting states with the Berry connection using the particle number
conserving version of the Bogoliubov-de Gennes equations. An example
calculation is made for a model originally built for cuprate
superconductors.

Subjects: Superconductivity (cond-mat.supr-con) Cite as: arXiv:2105.02364
[cond-mat.supr-con] (or arXiv:2105.02364v1 [cond-mat.supr-con] for this
version)