From GMR to TMR

Maekawa, Sadamichi; Ieda, Junichi   

A multilayer alternately stacked with several atomic layers of a ferromagnetic metal and those of a normal metal shows a drastic decrease in its electrical resistance in an applied magnetic field. This discovery in 1988, the giant magnetoresistance (GMR), has developed a new nanotechnology, the so-called spin-electronics (spintronics), offering a variety of issues which involve in magnetism and electrical conduction. Tunnel magnetoresistance (TMR) observed in a tunnel junction, which sandwiches in a few atomic layers of an insulator between ferromagnetic metals, attracts much attention these days both in fundamental and applied levels. Currently this stream leads to understandings of physical phenomena emerging from interactions between charge current and spin current in nanoscale materials.