Magnetic recording head, magnetic head assembly, magnetic recording apparatus, and magnetic recording method

A magnetic recording head, comprising:

• a first magnetic pole to apply a recording magnetic field to a magnetic recording medium;
• a spin torque oscillator provided parallel to the first magnetic pole;
• a first coil to magnetize the first magnetic pole;
• and
• a second coil to pass a current independently of the first coil.

A magnetic head assembly, comprising:

• a magnetic recording head including:
• a first magnetic pole to apply a recording magnetic field to a magnetic recording medium;
• a second magnetic pole provided parallel to the first magnetic pole;
• a spin torque oscillator at least of which portion is provided between the first magnetic pole and the second magnetic pole;
• a first coil to magnetize the first magnetic pole;
• a second coil through which a current is passed independently of the first coil;
• and
• a third coil through which a current is passed independently of both the first coil and the second coil,
• a head slider mounting the magnetic recording head;
• a suspension mounting the head slider onto an end thereof;
• and
• an actuator arm connected to the other end of the suspension.

A magnetic recording apparatus, comprising:

• a magnetic recording medium;
• a magnetic head assembly including:
• a magnetic recording head including:
• a first magnetic pole to apply a recording magnetic field to the magnetic recording medium;
• a second magnetic pole provided parallel to the first magnetic pole and;
• a spin torque oscillator at least of which portion is provided between the first magnetic pole and the second magnetic pole;
• a first coil to magnetize the first magnetic pole;
• a second coil through which a current is passed independently of the first coil;
• and
• a third coil through which a current is passed independently of both the first coil and the second coil,
• a head slider mounting the magnetic recording head;
• a suspension mounting the head slider onto an end thereof;
• and
• an actuator arm connected to the other end of the suspension,
• a signal processor to write and read a signal on the magnetic recording medium by using the magnetic recording head.

A magnetic recording apparatus, comprising:

• a magnetic recording medium;
• a magnetic recording head including:
• a first magnetic pole to apply a recording magnetic field to the magnetic recording medium;
• a second magnetic pole provided parallel to the first magnetic pole;
• a spin torque oscillator at least of which portion is provided between the first magnetic pole and the second magnetic pole;
• a first coil to magnetize the first magnetic pole;
• and
• a second coil through which a current is passed independently of the first coil, and
• a signal processor to write and read a signal on the magnetic recording medium by using the magnetic recording head, the signal processor including:
• a first current circuit to supply a recording current to the first coil, the recording current including a recording signal to be recorded on the magnetic recording medium;
• and
• a second current circuit to supply a modulating current to the second coil,
• wherein
• the modulating current includes either one of a signal changing at a frequency higher than that of the recording signal and a signal having the same frequency as the recording signal to change an absolute value thereof in one cycle.

A magnetic recording apparatus, comprising:

• a magnetic recording medium;
• a magnetic recording head including:
• a first magnetic pole to apply a recording magnetic field to the magnetic recording medium;
• a spin torque oscillator arranged parallel to the first magnetic pole;
• a first coil to magnetize the first magnetic pole;
• and
• a signal processor to write and read a signal on the magnetic recording medium by using the magnetic recording head, the signal processor including a first current circuit to supply a recording current to the first coil, the recording current including a recording signal to be recorded on the magnetic recording medium,
• wherein
• the recording current includes either one of a signal changing at a frequency higher than that of the recording signal, and a signal having the same frequency as the recording signal to change an absolute value thereof in one cycle.