A discovery that has helped hard drive makers cram even more data onto disks has won two scientists the 2007 Nobel Prize in physics.

Scientists Albert Fert, of France, and Peter Grunberg, of Germany, will share the prize for simultaneously discovering giant magnetoresistance (GMR), a physical effect that “opened the door to a new field of science, magnetoelectronics (or spintronics), where two fundamental properties of the electron, namely its charge and its spin, are manipulated simultaneously,” wrote the Stockholm-based Royal Swedish Academy of Sciences in its Nobel citation.

Fert is a professor with Université Paris-Sud in Orsay. Grunberg meanwhile is affiliated with the Research Centre Julich, in Julich, Germany.

They made their discovery in 1988, but within 10 years, the discovery was commercialised by vendors such as IBM, who developed ways of mass-producing hard drives that capitalised on this effect to store data much more densely than before.

Portable music players with high-capacity storage are a fruit of this revolutionary phenomenon, the Nobel citation noted. "With a music player in the pocket of each and everyone, few still stop to think about how many CDs' worth of music its tiny hard disk can actually hold," the citation said.

The GMR effect replaced earlier technology of induction coils as read-out heads in hard drives. Induction coils are still used to write data on the disk. IBM is now looking to apply GMR technology to tape storage and MRAM (magnetoresistive random access memory), memory that stores data bits using magnetic charges.