Ultrafast laser pulses shed light on elusive superconducting mechanism

Mar 29, 2012

An international team that includes University of British Columbia physicists has used ultra-fast laser pulses to identify the microscopic interactions that drive high-temperature superconductivity.

In the experiment, to be outlined this Friday in the journal Science, electrons in a prototypical copper-oxide superconductor were excited by extremely short 100-femtosecond laser pulses.

As the material's electrons relax back to an equilibrium state, they release their via deformation of the superconductor's atomic lattice () or perturbation of its magnetic correlations (spin fluctuations).

The researchers were able to capture very fine grained data on the speed of the relaxation process and its influence on the properties of the superconducting system, showing that the high-critical temperature of these compounds can be accounted for by purely electronic (magnetic) processes.

"This new technique offers us our best window yet on the interactions that govern the formation of these elusive superconducting properties--both across time and across a wide range of characteristic energies," says UBC Associate Professor Andrea Damascelli, Canada Research Chair in of Solids with the Department of Physics and Astronomy and the UBC Quantum Matter Institute.

"We're now able to begin to disentangle the different interactions that contribute to this fascinating behavior."

Superconductivity--the phenomenon of conducting electricity with no resistance--occurs in some materials at very low temperatures. High-temperature cuprate superconductors are capable of conducting electricity without resistance at temperatures as high as -140 degrees Celsius.

The key mechanism that allows the carriers to flow without resistance in superconductors stems from an effective pairing between electrons. In conventional metallic superconductors, this pairing mechanism is well understood as phonon-mediated. In copper-oxides, the nature of the low-resistance interaction between the electrons has remained a mystery.

"This breakthrough in the understanding of the puzzling properties of copper-oxides paves the way to finally solving the mystery of high-temperature superconductivity and revealing the key knobs for engineering new superconducting materials with even higher transition temperatures," says the paper's lead author Claudio Giannetti, a researcher with Italy's Università Cattolica del Sacro Cuore and visiting professor at UBC's Institute.

The international collaboration also involved contributions from Japanese, Swiss and American researchers.

Explore further: Physicist pursues superconductivity mysteries

More information: "Disentangling the Electronic and Phononic Glue in a High-Tc Superconductor," by S. Dal Conte, et al., Science.

Related Stories

Superconductivity's third side unmasked

Jun 17, 2011

The debate over the mechanism that causes superconductivity in a class of materials called the pnictides has been settled by a research team from Japan and China. Superconductivity was discovered in the pnictides ...

Secrets behind high temperature superconductors revealed

Feb 22, 2009

(PhysOrg.com) -- Scientists from Queen Mary, University of London and the University of Fribourg (Switzerland) have found evidence that magnetism is involved in the mechanism behind high temperature superconductivity.

Superconductivity: The puzzle is taking shape

Sep 13, 2011

By destabilizing superconductivity with a strong magnetic field, the electrons of a "high temperature" superconductor align into linear filaments. This phenomenon has been demonstrated by a team of researchers ...

Recommended for you

New largest number factored on a quantum device is 56,153

50 minutes ago

(Phys.org)—Researchers have set a new record for the quantum factorization of the largest number to date, 56,153, smashing the previous record of 143 that was set in 2012. They have shown that the exact same room-t ...

Scientists film magnetic memory in super slow-motion

4 hours ago

Researchers at DESY have used high-speed photography to film one of the candidates for the magnetic data storage devices of the future in action. The film was taken using an X-ray microscope and shows magnetic ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.