National High Magnetic Field Laboratory, NHMFL

Pulsed Field Facility News

April 26, 2006
By Susan Ray

Magnet Lab researchers Produce One of 2005's Top Physics Papers
LOS ALAMOS, N.M. - A paper on shape memory effect is leaving a lasting impression on the world of condensed matter physics.

The paper, "Fermi surface as a driver for the shape-memory effect in AuZn"has been chosen by Journal of Physics: Condensed Matter as of the Top Papers of 2005. The papers and review articles chosen for 2005 Showcase are considered to be the very best contributions of the last year.

"It makes all the long nights in the lab worthwhile when the result provokes so much interest," said Ross McDonald, the paper's lead author. McDonald is a scientist in the Pulsed Field Facility of the National High Magnetic Field Laboratory at Los Alamos, N.M.

The paper greatly contributes to the advancement of materials science. As summarized in the Showcase summary, "the dataand calculations provide direct evidence about the role of band-electron system and its Fermi surface in the shape memory effect, showing the band-structure/property relations are an important consideration for the design of future shape memory alloys."

Richard Palmer, publisher of the journal, said the top papers received the highest praise from the board of referees and were the most highly downloaded articles throughout 2005.

The Pulsed Field Facility at LANL is one of the most scientifically productive high-field labs in the world, with an impressive and ever growing list of papers published in the most respected journals. Alex Lacerda, associate director for the user operations for all three sites and director of the Pulsed Field Facility, said McDonald and his LANL collegues are very deserving of the recognition.

Having a staff with such rich research of its own is one reason why our users' program remains among the best in the world." said Lacerda

April 11, 2006
Susan Ray

Los Alamos, NM - The high-consequence lift of the National High Magnetic Field Laboratory/Department of the Energy 100 tesla magnet's outer coil set was safety completed this week at the lab's Pulsed Field Facility in Los Alamos, New Mexico. Weighing in at 18,000 pounds, the outer coil set - holding coils three through seven - used 90 percent of the crane's rated capacity."

The lift went smoothly and without incident. The section was lifted off the assembly stand, the over the cell maze wall, transferred into the cell and lowered into the dewar vessel. The section registered precisely into support features within the dewar.

Alex Lacerda, associate director for user operations for all three Magnet Lab sites and director of the Pulsed Field Facility, said that when completed the 100 T will represent a new technological limit.

Strength of science means renewal not-recompetition for the Magnet Laboratory. The National Science Foundation with the approval from the National Science Board has accepted a renewal proposal from the National High Magnetic Field Laboratory rather than hold a national competition for operation of the nation's magnet lab.

The unanimous NSF panel decision was based on reasons such as "science remains fertile, the infrastructure is magnificent, and outstanding performance by present management. The NHMFL grant renewal is "in the best interest of science and engineering."

Bob Richardson, Nobel Prize winner in physics, chaired a 2005 NSF Blue Ribbon Panel review of the NHMFL. The panel also strongly advised NSF to renew the NHMFL grant. The magnet laboratory is funded in five-year cycles and currently receives about $25 million a year from the National Science Foundation.

NHMFL News
NHMFL-Rice University collaboration reveals insight into optical properties of single-walled nanotubes. Reseach into the optical properties of single-walled carbon nanotubes, performed by researchers at Rice University in collaboration with MPA-NHMFL's Scott Crooker and Madalina Furis, in collaboration with researchers at Rice University, is the focus of "Exciton in Carbon Nanotubes with Broken Time-Reversal Symmetry," which is published in Physical Review Letters (PRL, 96, 016406, 2006).

In work performed at Los Alamos' National High Magnetic Field Laboratory and led by Jun Kono of Rice University, near-infrared magneto-optical spectroscopy of single-walled carbon nanotubes revealed two absorption peaks with an equal strength in ultra-high pulsed magnet fields to 75T. The researchers showed that the peak separation is determined by the Aharonov-Bohm phase due to the tube-threading magnetic flux, which breaks the time-reversal symmetry and lifts the valley degeneracy. This field-induced symmetry breaking thus overcomes the Coulomb-induced intervalley mixing which is predicted to make the lowest exciton state optically inactive (or "dark").

The research provides scientists with new understanding of the fundamental optical properties of semiconducting nanotubes, which could potentially allow engineers to design more powerful ad efficient computer chips based on the manipulation of optical, rather than electrial, signals. Link to PRL

Authors are S. Zaric, G.N. Ostojic, J. Shaver, J.Kono, V.Moore, R. Hauge, R. Smalley, Rice University; O. Portugal, P.H. Frings, G.L. J.A. Rikken, Laboratoire National des Champs Magnétiques Pulsés in Toulouse, France; and X. Wei, National High Magnetic Field Laboratory at Florida State University. LA-UR 05-7783

Neil Harrison Receives 2005 Los Alamos Fellows' Prize for Outstanding Research
Ground-breaking discoveries and outstanding contributions to the field of condensed matter physics have earned Neil Harrison a pretigious 2005 Los Alamos Fellows' Prize for Outstanding Research.

Harrison, a staff scientist at the National High Magnetic Field Laboratory's Pulsed Field Facility in Los Alamos, New Mexico was recognized for his work using high magnetic fields to make pioneering discoveries in strongly correlated materials. The Fellows' Prize for Research honors those who make a significant impact in the scientific field.