Albert Fert
active c. 1938, Carcassonne, France
French physicist who co-discovered giant magnetoresistance (GMR) in 1988 — the effect that shrank hard drives a thousandfold and opened the field of spintronics.
Fert earned his PhD at the University of Paris in 1963 and became professor at Paris-Sud (Orsay) in 1976, also heading the joint CNRS/Thales laboratory from 1988.
Research on magnetic alloys led him to ultrathin Fe/Cr multilayers, where he found resistance dropping by up to 50% under a magnetic field — giant magnetoresistance. Within a decade the effect was in hard-drive read heads, launching the data-storage revolution and the field of 'spintronics'. He shared the 2007 Nobel with Peter Grünberg.
Nobel-winning work
In Fe/Cr multilayers — iron layers a few nanometers thick alternating with chromium — Fert's group found in 1988 that resistance dropped sharply (~50%) when an external field forced the magnetic layers to align. The reason: 'spin-up' and 'spin-down' electrons scatter differently in each magnetic layer; with anti-aligned layers, both spin channels scatter strongly — high resistance; aligned, one channel passes nearly freely — low resistance.
This 'giant magnetoresistance' was tens of times more sensitive than previous magnetic sensors and worked at room temperature. IBM put GMR into hard-drive read heads in 1997, multiplying data density year after year; today spin valves, magnetic RAM, and GMR sensors are everywhere. The 2007 Nobel cited 'the discovery of giant magnetoresistance'.
Workplaces: Université Paris-Sud, CNRS/Thales
France