Energy News  
ENERGY TECH
Theory gives free rein to superconductivity at room temperature
by Staff Writers
Moscow, Russia (SPX) May 25, 2018

Bose-Einstein condensate - is a state of matter which was predicted by Albert Einstein and Satyendra Nath Bose in 1925. The condensate in itself was produced 70 years later, in 1995, by Eric Cornell and Carl Wieman in a gas of rubidium cooled to nearly absolure zero (1,7+ 10-7 K). For their achievements Cornell and Wieman received the Nobel Prize in 2001. In a Bose-condensate all the particles move consistently. (illustration only)

Development of superconductors which can operate at room temperature has been a major focus of interest of physicists all over the world. At times news come out about the discovery of new high-temperature (HTSC) materials which brings hope that such superconductors will be developed.

At present, however, a unified theory of such materials is lacking. Victor Lakhno, a physicist from Keldysh Institute of Applied Mathematics, suggested to take the translation-invariant bipolaon theory as a basis. In the paper published in Advances in Condensed Matter Physics possible ways of solving the room-temperature superconductivity problem are presented.

Generally accepted BCS theory for which its originators Bardeen, Cooper and Schrieffer were awarded the Noble Prize in 1972, discarded the phenomenon of superconductivity at temperature close to absolute zero (near -270C). However in 1986 by way of experiments Alex Muller and Georg Bednorz found a molecular entity belonging to the class of high-temperature superconducting cuprates La2-xBaxCuO4 (?=-243C), for what they also received the Nobel Prize. These materials received the name HTCS materials. By now scientists have already created materials superconducting at temperatures up to -70Celsius.

Today the main problem is to develop of a microscopic theory capable of explaining experimental facts which cannot be accounted for by the standard BCS theory. This has given rise to a multitude of new explanations of the superconductivity mechanism. One of them is a bipolaron scenario.

Victor Lakhno, head of the Laboratory of Quantum-Mechanical Systems of the Institute of Mathematical Problems of Biology, RAS - the Branch of Keldysh Institute of Applied Mathematics RAS has calculated a critical temperature of the transition, energy, heat capacity and heat of transition of an ideal three-dimensional Bose-condensate of translation-invariant bipolarons (TI-bipolarons). The results obtained offer an explanation of the experiments with high-temperature superconductors.

Bose-Einstein condensate - is a state of matter which was predicted by Albert Einstein and Satyendra Nath Bose in 1925. The condensate in itself was produced 70 years later, in 1995, by Eric Cornell and Carl Wieman in a gas of rubidium cooled to nearly absolure zero (1,7+ 10-7 K). For their achievements Cornell and Wieman received the Nobel Prize in 2001. In a Bose-condensate all the particles move consistently.

They form one quantum-mechanical wave and behave like one huge particle. All of them are located in one and the same place and at the same time each of them is "spread" over the whole region of space. Victor Lakhno mathematically proved that a quantum Bose-gas consisting of translation-invariant bipolarons in a one-dimensional conductor can give birth to a Bose-condensate.

A polaron is a quasiparticle consisting of electrons and excitations which electrons induce while moving through a crystal lattice. Such excitations are called phonons. The notion of a polaron was introduced by a soviet physicist Solomon Pekar in 1946. Later the theory of polarons was developed by Alexander Tulub who found a new solution of the polaron problem for the case of a strong interaction between an electron and a lattice.

A bipolaron is a pair of polarons bounded by a phonon interaction. Victor Lakhno has managed to show that a polaron can be translation-invariant, i.e. be a plane wave running in a crystal lattice. He theoretically proved that translation-invariant bipolarons can produce a stable Bose-condensate in stripes even at room temperature. This means that superconductivity at these temperatures is possible.

In his calculations he proceeded from the same factors as the classical BCS theory did. However He excluded the electron variables from the Froehlich Hamiltonian of electron-phonon interaction instead of the phonon ones. Since in the case of a linear dispersion law (as in the BCS) phonons represent quantized acoustic waves, it can be said that in the TI-bipolaron theory, SC is caused by charged acoustic waves which form a SC condensate.

In the case of HTSC materials, according to his theory, we deal not with acoustic phonons, but with optic ones since these materials are ionic crystals. As a result, the theory describes a charged Bose gas of optical phonons coupled with electron pairs which are translation-invariant (TI) bipolarons. Like Cooper pairs TI-bipolarons are plane waves possesing a small correlation length equal to several constants of the crystal lattice.

The qualitative difference of this theory from the other ones is that it implies that even at zero temperature only a small portion of all the electrons are in the TI-bipolaron (paired) state. This corresponds to the results obtained in Bo?ovi? et al experiments in 2016 and opens up new opportunities for creation of room-temperature superconductors. Since this theory suggests that in order to enhance the critical temperature of the transition, one should enhance the concentration of TI-bipolarons.

Viktor Lakhno tells: "To produce a superconducting cable operable at room temperature one should use strongly underdoped HTSC material (whose SC transition temperature is very low, i.e. a few K). This material, however, already contains bipolarons, though in very small quantity. It only remains to enhance their concentration without resort to doping. This can be arranged by making the cable coaxial so that the internal small-diameter cable isolated from the external one could induce a strong electric field attracting bipolarons".

Earlier the problem has never been formulated in this way, since it was believed that at low temperatures all the electrons are paired anyway and one can only enhance the concentration of electrons, not their pairs.

Research paper


Related Links
AKSON Russian Science Communication Association
Powering The World in the 21st Century at Energy-Daily.com


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


ENERGY TECH
Simple equation directs creation of clean-energy catalysts
Lincoln NB (SPX) May 15, 2018
New guidelines laid down by Nebraska and Chinese researchers could steer the design of less costly, more efficient catalysts geared toward revving up the production of hydrogen as a renewable fuel. Nebraska's Xiao Cheng Zeng and colleagues have identified several overlooked factors critical to the performance of single-atom catalysts: individual atoms, usually metallic and anchored by surrounding molecular frameworks, that kick-start and accelerate chemical reactions. The team folded those v ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

ENERGY TECH
Top US court to examine India power plant complaint

Portugal's EDP rejects Chinese takeover offer

New phase of globalization could undermine efforts to reduce CO2 emissions

Carbon taxes can be both fair and effective, study shows

ENERGY TECH
Polymer crystals hold key to record-breaking energy transport

China's Tianqi raises profile as a top lithium supplier with stake in Chile's SQM

Using 3D X-rays to measure particle movement inside lithium ion batteries

Microscopy advance reveals unexpected role for water in energy storage material

ENERGY TECH
U.S. Atlantic states eye offshore wind leadership

European wind energy generation potential in a warmer world

New York to world's largest offshore wildlife aerial survey

German utility E.ON sees renewable sector growth

ENERGY TECH
Black Bear Energy And Usaa Real Estate Announce 2.4 Megawatt New Jersey Solar Project

Germany's E.ON explores solar development with Google

LBA Realty's Battery Storage and LED Projects expected to deliver $1.9 million in Energy Savings

ABC Solar Seeking Legal Funds from CrowdJustice.com for Monopoly Abuse Fight

ENERGY TECH
Framatome to provide Dominion Energy with steam generator services

Supreme Court to rule on largest uranium deposit in US

GE Hitachi Announces Dominion Energy as Investor in BWRX-300 Small Modular Reactor

Nuclear Waste Management Organization Signs Co-Operation Agreements With International Partners

ENERGY TECH
Advanced biofuels can be produced extremely efficiently, confirms industrial demonstration

Technique doubles conversion of CO2 to plastic component

New catalyst upgrades greenhouse gas into renewable hydrocarbons

Scientists have deciphered the chemical reaction mechanism critical for cleaner combustion

ENERGY TECH
Upstream efforts put North Sea find closer to production

Economic, trade concerns drag oil prices lower

Europe tries to correct Gazprom's behavior

No easy fix to higher gas prices in United States

ENERGY TECH
Climate change in Quebec equals a much greater diversity of species?

Schwarzenegger urges Trump to 'join us' on climate action

GRACE-FO Will Help Monitor Droughts

Projecting climate change along the Millennium Silk Road in a warmer world









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.