Physicists are one step closer to developing the world’s first room-temperature superconductor thanks to a new theory from the University of Waterloo, Harvard and Perimeter Institute.
The theory explains the transition phase to superconductivity, or “pseudogap” phase, which is one of the last obstacles to developing the next generation of superconductors and one of the major unsolved problems of theoretical condensed matter physics.
Their work was published in this week’s issue of the prestigious journal Science.
Superconductivity is the phenomenon where electricity flows with no resistance and no energy loss. Most materials need to be cooled to ultra-low temperatures with liquid helium in order to achieve a superconductive state.
The team includes Professor Roger Melko, Professor David Hawthorn and doctoral student Lauren Hayward from Waterloo’s Physics and Astronomy Department, and Harvard Physics Professor Subir Sachev. Roger Melko also holds a Canada Research Chair in Computational Quantum Many-Body Physics.
Hawthorn showed Sachdev his latest experimental data on a superconducting material made of Copper and the elements Yttrium and Barium. The material, YBa2Cu3O6+x, had an unexplained temperature dependence. Sachdev had a theory but needed expert help with the complex set of calculations to prove it. That’s where Melko and Hayward stepped in and developed the computer code to solve Sachdev’s equations.
Melko and Sachdev already knew each other through Perimeter Institute, where Melko is an associate faculty member and Sachdev is a Distinguished Research Visiting Chair.
“The results all came together in a matter of weeks,” said Melko. “It really speaks to the synergy we have between Waterloo and Perimeter Institute.”
To understand why room-temperature superconductivity has remained so elusive, physicists have turned their sights to the phase that occurs just before superconductivity takes over: the mysterious “pseudogap” phase.
“Understanding the pseudogap is as important as understanding superconductivity itself,” said Melko.
The cuprate, YBa2Cu3O6+x, is one of the few materials known to be superconductive at higher temperatures, but scientists are so far unable to achieve superconductivity in this material above -179°C. This new study found that YBa2Cu3O6+x oscillates between two quantum states during the pseudogap, one of which involves charge-density wave fluctuations. These periodic fluctuations in the distribution of the electrical charges are what destabilize the superconducting state above the critical temperature.
Once the material is cooled below the critical temperature, the strength of these fluctuations falls and the superconductivity state takes over.
Superconducting magnets are currently used in MRI machines and complex particle accelerators, but the cost of cooling materials using Helium makes them very expensive. Materials that achieve superconductivity at a higher temperature could unlock the technology for new smart power grids and advanced power storage units.
The group plans to extend their work both theoretically and experimentally to understand more about the fundamental nature of cuprates.
In just half a century, the University of Waterloo, located at the heart of Canada's technology hub, has become one of Canada's leading comprehensive universities with 35,000 full- and part-time students in undergraduate and graduate programs. Waterloo, as home to the world's largest post-secondary co-operative education program, embraces its connections to the world and encourages enterprising partnerships in learning, research and discovery. In the next decade, the university is committed to building a better future for Canada and the world by championing innovation and collaboration to create solutions relevant to the needs of today and tomorrow. For more information about Waterloo, please visit www.uwaterloo.ca.
Attention broadcasters: Waterloo has facilities to provide broadcast quality audio and video feeds with a double-ender studio. Please contact us to book.
Nick Manning | EurekAlert!
A quantum walk of photons
24.05.2017 | Julius-Maximilians-Universität Würzburg
Scientists propose synestia, a new type of planetary object
23.05.2017 | University of California - Davis
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
23.05.2017 | Event News
22.05.2017 | Event News
17.05.2017 | Event News
24.05.2017 | Life Sciences
24.05.2017 | Life Sciences
24.05.2017 | Physics and Astronomy