Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Helping superconductors turn up the heat

A team of physicists from the University of Miami introduces a breakthrough in the understanding of high-temperature superconductivity

Researchers from the University of Miami (UM) are unveiling a novel theory for high-temperature superconductivity. The team hopes the new finding gives insight into the process, and brings the scientific community closer to achieving superconductivity at higher temperatures than currently possible. This is a breakthrough that could transform our world.

Superconductors are composed of specific metals or mixtures of metals that at very low temperatures allow a current to flow without resistance. They are used in everything from electric devices, to medical imaging machines, to wireless communications. Although they have a wide range of applications, the possibilities are limited by temperature constraints.

"Understanding how superconductivity works at higher temperatures will make it easier to know how to look for such superconductors, how to engineer them, and then how to integrate them into new technologies," says Josef Ashkenazi, associate professor of physics at the UM College of Arts and Sciences and first author of the study. "It's always been like this when it comes to science: once you understand it, the technological applications follow."

At room temperature, superconducting materials behave like typical metals, but when the temperature is lowered toward absolute zero (at around -273oC, or -460oF), resistance to electric current suddenly drops to zero, making it ultra-efficient in terms of energy use. Although absolute zero is unachievable, substances such as liquid helium and liquid nitrogen can be used to cool materials to temperatures approaching it.

Researchers are also working on creating materials that yield superconductivity in a less frigid environment. The point at which a matter becomes a superconductor is called critical or transition temperature. So far, the highest critical temperature of a superconducting material is about -130oC (-200oF).

"But just 'cooking' new materials that produce superconductivity at higher temperatures can be very tedious and expensive, when one doesn't know exactly how the process works," says Neil Johnson, professor of physics in the UM College of Arts and Sciences and co-author of the study.

To understand the problem, the UM team studied what happens in a metal at the exact moment when it stops being a superconductor. "At that point, there are great fluctuations in the sea of electrons, and the material jumps back and forth between being a superconductor and not being one," Johnson says.

The key to understanding what happens at that critical point lies in the unique world of quantum particles. In this diminutive universe, matter behaves in ways that are impossible to replicate in the macroscopic world. It is governed not by the laws of classical physics, but by the laws of quantum mechanics.

One of the most perplexing features of quantum mechanics is that a system can be described by the combination or 'superposition' of many possible states, with each possible state being present in the system at the same time. Raising the critical temperature of superconductors is prevented in common cases, because it creates a fragmentation of the system into separate states; this act suppresses high-temperature superconductivity.

What Ashkenazi and Johnson found is that just above the critical temperature specific quantum effects can come to the floor and generate superpositions of individual states. This superposition of states provides an effective "glue," which helps repair the system, allowing superconducting behavior to emerge once again. This model provides a mechanism for high temperature superconductivity.

"Finding a path to high-temperature superconductivity is currently one of the most challenging problems in physics," says Ashkenazi. "We present for the first time, a unified approach to this problem by combining what has prevented scientists from achieving high-temperature superconductivity in the past, with what we now know is permitted under the quantum laws of nature."

"The new model combines elements at two levels: physically pulling together the fragments of the system at the quantum level, and theoretically threading together components of many other existing theories about superconductivity," Johnson says.

Understanding how superconductivity is pushed beyond the present critical temperatures will help researchers recreate the phenomenon at a wider temperature range, in different materials, and could spur the development of smaller, more powerful and energy efficient technologies that would benefit society.

The study, titled "Pairing Glue Activation in Curates within the Quantum Critical Regime," is published online ahead of print by the journal Europhysics Letters.

The University of Miami's mission is to educate and nurture students, to create knowledge, and to provide service to our community and beyond. Committed to excellence and proud of our diversity of our University family, we strive to develop future leaders of our nation and the world.

Annette Gallagher | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)

nachricht Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>