Magnetic head device and magnetic disk drive apparatus with the magnetic head device

A magnetic disk drive apparatus having a magnetic disk, a magnetic head device with a magnetic head section, and a support means for supporting said magnetic head section so that said magnetic head section opposes to a surface of said magnetic disk, said magnetic head device comprising:

• the magnetic head section including a first free layer with a magnetization orientation that is not previously defined but changes depending upon only external magnetic field applied, a second free layer with a magnetization orientation that is not previously defined but changes depending upon only external magnetic field applied, a nonmagnetic intermediate layer sandwiched between said first free layer and said second free layer, a first electrode layer stacked on a surface of said first free layer opposite to said nonmagnetic intermediate layer, and a second electrode layer stacked on a surface of said second free layer opposite to said nonmagnetic intermediate layer;
• a sense-current supply means for flowing a sense current across said first electrode layer and said second electrode layer of said magnetic head section;
• and
• a frequency divider circuit for dividing by two a frequency of an output signal produced across said first electrode layer and said second electrode layer of said magnetic head section.