A spin valve GMR sensor configured in a bridge configuration is provided.
The bridge includes two spin valve element pairs. The spin valve elements
include a free layer, a space layer, a pinned layer, and a bias layer.
The bias layer includes a first bias layer and a second bias layer. The
first and second spin valve element pairs are formed on separate metal
layers and a current pulse is applied to the metal layers, which sets the
direction of magnetization in the pinned layer of the first pair of spin
valve elements to be antiparallel to the direction of magnetization in
the pinned layer of the second pair of spin valve elements. The same
effect can be accomplished by making the pinned layer substantially
thicker than the second bias layer in the first spin valve element pair
and the pinned layer is substantially thinner than the second bias layer
in the second spin valve element pair and applying a magnetic field to
the first and the second spin valve element pairs.