Response of a spin valve to a spin battery

Abstract

It is shown that spin valves under suitable symmetry conditions exhibit an ON-OFF response to a spin battery, and are therefore perfect spin transistors. While a spin valve driven by a charge battery displays the usual GMR (Giant Magneto-Resistance), this means that a pure spin current or pure spin accumulation can generate an infinite magnetoresistance (IMR). Magnetic tunnel junctions as well as CPP (current perpendicular to plane) or CIP (current in plane) metallic trilayers are discussed.