Somewhere around the middle of my time as undergraduate, I discovered personal computers that did not require a minimum of three floppy disks just to write a short paper. The vastly superior capability of such machines was courtesy of the internal hard disk drive, which on an IBM 8080 held about 20MB. While hard disk drives, created way back in 1953, were by no means new in the 1980’s, the proliferation of PC’s equipped with hard drives–able store the computer’s operating system, application software, and a considerable amount of user data–greatly enabled of the explosion of personal computing that took place during the second half of that decade. By the time I had registered for my first graduate course, the popularity of the graphical user interface (GUI), systems requiring a large amount of disk space, foreshadowed the need for ever-increasing disk capacity in the years to come.

Coincident to these events, two European physicists, Albert Fert of France and Peter Grünberg of Germany, working independent of each other, described an exciting natural phenomenon within the realm of solid state physics. This was the dramatic decrease in electrical resistance in structures of ferromagnetic thin films interspersed with non-ferromagnetic layers, called multilayers, in the presence of an outside magnetic field. Their discovery was dubbed by Fert as Giant Magnetoresistance (GMR).

Professors Fert and Grünberg both reported the realization of GMR in separate articles published by the American Physical Society in the journals Physical Review Letters and Physical Review B (Condensed Matter and Material Physics) in 1988 and 1989, respectively. The discovery signaled a solitary advance in pure science by explaining the mechanisms by which GMR could be achieved. And, as often occurs when one of nature’s secrets is revealed, applications of the new understanding were soon to follow in the form of technologic advance.

In the decade that followed Fert and Grünberg’s production of GMR, research and development teams, having recognized the potential of the discovery, increased exponentially the capacity of hard drive storage devices by incorporating multilayer composite materials into hard drive read heads. This modification made the read heads considerably more sensitive, allowing much more information to be encoded onto disk drives’ platters.

For their work, Fert and Grünberg were jointly awarded the 2007 Nobel Prize in Physics.

In An Idiosyncratic History of Giant Magnetoresistance, our second issue of NSDL Classic Articles in Context, Prof. Peter M. Levy of New York University presents a journey through pure and applied scientific investigation as reported in 25 formative research papers.

It begins with a problem examined in various forms by physicists from the early and mid-twentieth century, including Nobel Laureates Sir Neville Mott and Louis Néel. The collection then gives attention to studies made within the past 15-20 years–after the discovery of GMR–which led to significant technologic advance and continue to open up entire new fields of investigation.

As always we are most grateful to the Publishers and their critical journals–including The American Association for the Advancement of Science, Science; The American Physical Society, Physical Review Letters & Physical Review B; Elsevier, The Journal Magnetism and Magnetic Materials; The Institute of Physics, Proceeding of the Physical Society; Nature Publishing Group, Nature; and The Royal Society, Proceedings of the Royal Society–who collaborated with NSDL in compiling this issue.