SAN JOSE, Calif.  The ability to cram more data into less space on a memory chip or a hard drive has been the crucial force propelling consumer electronics companies to make ever smaller devices.

It shrank the mainframe computer to fit on the desktop, shrank it again to fit on our laps and again to fit into our shirt pockets.

Now, if an idea that Stuart S. P. Parkin is kicking around in an I.B.M. lab here is on the money, electronic devices could hold 10 to 100 times the data in the same amount of space. That means the iPod that today can hold up to 200 hours of video could store every single TV program broadcast during a week on 120 channels.

The tech world, obsessed with data density, is taking notice because Mr. Parkin has done it before. An I.B.M. research fellow largely unknown outside a small fraternity of physicists, Mr. Parkin puttered for two years in a lab in the early 1990s, trying to find a way to commercialize an odd magnetic effect of quantum mechanics he had observed at supercold temperatures. With the help of a research assistant, he was able to manipulate the alignment of electronics to alter the magnetic state of tiny areas of a magnetic data storage disc, making it possible to store and retrieve information in a smaller amount of space. The huge increases in digital storage made possible by giant magnetoresistance, or GMR, made consumer audio and video iPods, as well as Google-style data centers, a reality.