The present invention provides a tunneling magneto-resistive read sensor structure
that improves sensitivity and linear density of the sensor structure. The sensor
includes first and second electrodes and a stack positioned between the electrodes.
The stack includes first and second free layers with magnetization orientations
that are biased relative to each other. A tunneling barrier (insulating layer)
or non-magnetic metal spacer is positioned between the first and second free layers.
A sense current is passed between the first and second free layers of the stack.
The amount of current passing through the first and second free layer changes based
upon the orientation of the first and second free layers relative to each other.