Jun 23 2014
The U.S. Department of Energy (DOE) has announced an extension of funding totaling $14 million over four years for an Energy Frontier Research Center (EFRC) first established at DOE's Brookhaven National Laboratory in 2009. It is one of 32 EFRCs announced by U.S. Energy Secretary Ernest Moniz to accelerate the scientific breakthroughs needed to build the 21st-century energy economy.
"We are mobilizing some of our most talented scientists to join forces and pursue the discoveries and breakthroughs that will lay the foundation for our nation's energy future," Secretary Moniz said.
Dubbed the Center for Emergent Superconductivity, the EFRC is led by Brookhaven with partners from the University of Illinois and DOE's Argonne National Laboratory with the aim of understanding the fundamental nature of superconductivity in complex materials-a potentially transformative property that could revolutionize energy distribution and storage.
Unlike ordinary conductors, superconductors carry electric current with zero resistance, so no energy is lost as it travels through these materials. At the Center for Emergent Superconductivity, collaborating scientists are exploring methods to improve the critical properties of known "high-temperature" superconducting materials-which operate above the extreme cold temperatures required for conventional superconductivity-and accelerate the search for new ones. The key challenges are figuring out what causes electrons in these materials to overcome their repulsive tendency and instead pair up to carry current with no loss-and then finding ways to make this happen at even warmer temperatures more suitable for real-world applications without the need for expensive coolants.
"Finding the keys that unlock the secrets of high-temperature superconductivity would transform our ability to transport and store vast quantities of energy," said Brookhaven senior physicist J.C. Séamus Davis, who directed the Center for Emergent Superconductivity from its inception and who is also a professor at both Cornell University and the St. Andrews University in Scotland.
Peter Johnson, Chair of the Brookhaven's Condensed Matter Physics and Materials Science Department, who will direct the Center under the renewal, added, "These are crucial issues for this nation-and the world-especially as we aim to make greater use of renewable energy sources like solar and wind power. High-temperature superconductors could ease the integration of these intermittent energy sources while also improving the capacity, efficiency, and reliability of the entire electric grid."
Brookhaven scientists and their collaborators in the Center have produced a series of discoveries elucidating the intricate behavior of electrons and their properties in high-temperature superconductors. These studies have revealed that, in these materials, electrons take on a wide variety of "ordered" arrangements, sometimes pair up at a temperature higher than that at which superconductivity sets in, can sometimes move more easily in a given direction dependent on the materials' atomic scale structure, and can exist in an array of different phases that may compete with superconductivity and so must be understood.
The experiments rely on precision techniques and tools installed and cultivated at Brookhaven, Argonne, and the University of Illinois as part of the EFRC and through other DOE Office of Science funding. These tools enable scientists to create exquisite samples of superconductors and explore their exotic electron behaviors in ever-greater detail. Tools include:
- Furnaces for synthesizing perfect single crystals
- Methods for building composite materials one atomic layer at a time
- An accelerator at Argonne that bombards superconductors with beams of ions to freeze magnetic spin vortices in place to better understand their role in superconductivity and, in particular, in enabling these materials to carry more current in the superconducting state
- X-ray imaging techniques at Brookhaven's National Synchrotron Light Source (NSLS), a DOE Office of Science user facility, and soon-to-be-open NSLS-II-which will have 10,000 times the brightness for greatly increased resolution
- Spectroscopic tools such as scanning tunneling microscopy (SI-STM), which allows simultaneous measurement of electron positions and energy levels to spot atom-by-atom differences in electron behavior, and angle-resolved photoemission, which allows the measurement of the electrons' properties as a function of their direction of motion.
"The new tools invented, refined, and installed as part of this EFRC complement the capabilities of the traditional 'big machines' supported by DOE at the national labs," Johnson said. "Together these tools are providing unprecedented insight into the mechanisms of high-temperature superconductivity."
The DOE competition for funding was open to proposals both from existing EFRCs seeking renewal of support and from institutions seeking to establish new EFRCs. Brookhaven's Center for Emergent Superconductivity was one of 22 EFRCs that received renewed funding and 10 new centers selected from among 200 proposals.
Selections were made based on a competitive merit review using panels of outside experts. Projects were selected for renewed funding based both on their achievements to date and the merits of their proposals for future research.
"All the members of the Center for Emergent Superconductivity across our three institutions are delighted by the renewal of the Center and enthusiastic to return to the challenge of discovering and developing new and better superconductors," Davis said.