Germany's Peter Gruenberg and France's Albert Fert independently discovered the phenomenon, called "giant magnetoresistance," in 1987.
Both scientists found that by sandwiching together thin layers of magnetic and nonmagnetic atoms, they could make a new material with useful electromagnetic properties. Outside of a magnetic field, the layered material had high electrical resistance--it wouldn't transmit an electrical current. But when exposed to a magnetic field, the material would easily transmit electricity.
This ability to convert tiny magnetic inputs has allowed scientists to create ever-smaller hard disks. The disks store data magnetically, and these weak magnetic changes can be detected and converted to electrical signals for computer chips to read. These small hard disks are included in popular portable electronic devices like laptops, iPods and other MP3 players.
"The MP3 and iPod industry would not have existed without this discovery," Borje Johansson, a member of the Royal Swedish Academy of Sciences, told the Associated Press.
National Institute of Standards and Technology physicist Julie Borchers, who was a graduate student in the 1980s, remembers attending meetings with Fert and Gruenberg during her studies.
"It was so exciting because everyone realized what the potential applications were," she told the Chronicle of Higher Education. However, she says, the research "was really driven by the desire to understand the pure science behind it."
Surrounded by reporters in Paris soon after learning of his award, the 69-year-old Fert started chatting with some youngsters nearby, Reuters reported.
"You like physics?" he asked, telling them he had just won the Nobel prize. "If you are able to listen to music on your MP3 player, it is a bit thanks to what I've done."