The Nobel Prize in Physics this year will go to two scientists, from Germany and France, who in 1988 independently discovered a magnetic phenomenon that led to the hard-disk drives used in computers today.
Albert Fert, a professor at the University of Paris-Sud, and Peter Grünberg, of the German Research Center in Jülich, will share the $1.5-million prize, for their discovery of "giant magnetoresistance," which is "one of the first real applications of the promising field of nanotechnology," according to the Royal Swedish Academy of Sciences.
The prize for their work "was overdue because it's such a great achievement," said Reinhold Koch, a professor of solid-state physics at the University of Linz, in Austria, who is trying to develop new computing applications from the same physical effect.
It has been a year of accolades for Mr. Fert, 69, and Mr. Grünberg, 68, who shared the Japan Prize and Israel's Wolf Prize in 2007.
Heroic Sandwich
The work that garnered such attention began with basic physical investigations into the magnetic properties of extremely thin sheets of matter. In the 1980s, several scientists around the world were creating sandwiches in which a nonmagnetic layer only a few atoms thick was pressed between magnetic layers.
When Mr. Grünberg made a nanoscale sandwich of chromium between two slices of iron, he found it had startling electrical properties. Outside of a magnetic field, the sandwich would not easily transmit an electrical current. But when the sandwich was placed in a magnetic field, the resistance dropped significantly, and a current could pass more easily through the material.
Mr. Fert created a multilayered sandwich of alternating iron and chromium and found even larger effects. He called this phenomenon "giant magnetoresistance" because it demonstrated much larger electrical changes in the presence of magnetic fields than scientists had seen before.
"The discovery of giant magnetoresistance immediately opened the door to a wealth of new scientific and technological possibilities, including a tremendous influence on the technique of data storage and magnetic sensors," according to the Swedish academy.
Both Mr. Fert and Mr. Grünberg recognized the potential of their discoveries, and Mr. Grünberg filed for a patent on it. Within a decade, the sandwich technology was being used in the sensors that read data in computer hard drives. The data are stored on hard drives as tiny magnetic patches. As a sensor passes over an individual patch, the magnetic field alters how an electrical current passes through the sandwich.
An article by Mr. Grünberg in a 2001 issue of Physics Today gave an overview of how the field had been revolutionized, in part, by their findings.
Packed Data, Packed Room
Earlier computers used a slower system that took up more room, which meant that less data could be packed onto a disk. "This enabled a dramatic increase in the amount of material you could store in a small space," said Julie A. Borchers, a research physicist at the National Institute of Standards and Technology, in Gaithersburg, Md., who was a graduate student working in this area in the 1980s.
She recalled the excitement of attending meetings at which Mr. Fert, Mr. Grünberg, and others presented their latest data. "There would be arguments, they would debate," she said. "The rooms would be packed. It was so exciting because everyone realized what the potential applications were." At the same time, she said, "it was really driven by the desire to understand the pure science behind it."
In fact, the story of giant magnetoresistance could be seen as a textbook example of the value of basic research ¿a point not lost on the scientists who chose this year's winners. "It is a very good demonstration of how a totally unexpected scientific discovery can give rise to completely new technologies and commercial products," according to the Swedish academy.
Researcher Left Out?
Nobel watchers have long had giant magnetoresistance on their list of discoveries with the potential to produce prize winners, but some wonder whether the Swedish academy overlooked a third scientist who contributed to work in the area. In its description of this year's award, the academy also credits Stuart Parkin, a researcher at the IBM Almaden Research Center, in San Jose, Calif., for his "important step" of developing an easier way to make the special nanosize sandwiches. In 1994 the American Physical Society awarded its James C. McGroddy Prize for New Materials to Mr. Grünberg, Mr. Fert, and Mr. Parkin.
Mr. Parkin is "very accomplished, and he's made tremendous contributions to the field," said Ms. Borchers, who declined to say whether she felt he deserved to share the prize. Physicists had floated his name in recent years as a potential Nobel nominee, she said. He was not a co-recipient of the Japan Prize or the Wolf Prize this year.
Today's announcement was the second Nobel Prize awarded this week. On Monday three scientists won the Nobel Prize in Medicine or Physiology for their work on mouse genetics.
