A data storage device is disclosed comprising a first head actuated over the first disk surface, and a second head actuated over a second disk surface. A concurrent access of the first and second disk surface is executed by accessing the first disk surface without accessing the second disk surface during a single access interval, and after the single access interval, concurrently accessing the first and second disk surface during a dual access interval.

According to one embodiment, a magnetic disk device includes a magnetic disk, a first magnetic head, a second magnetic head, a buffer memory, and a control circuit. The magnetic disk includes a plurality of first storage regions. The control circuit controls the first magnetic head to read first data from a second storage region of the first storage regions to the buffer memory. The control circuit controls the second magnetic head to write second data to a third storage region concurrently with the reading of the first data. The third region is of the first storage regions, different from the second storage region. The second data corresponds to the first data stored in the buffer memory.

According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a magnetic element provided between the first and the second magnetic poles. The magnetic element includes first to fourth magnetic layers, and first to fifth non-magnetic layers. The fourth magnetic layer includes a first element and at least one of Fe, Co or Ni. The first element including at least one selected from the group consisting of Cr, V, Mn, Ti, N and Sc. The fourth non-magnetic layer including at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag. The fifth non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag.

Systems and techniques relate to current slew control circuits. According to an aspect, a system implementing the quadratic slew control aspects comprises a disk; a read/write head; and a slew control circuit coupled to the read/write head, the slew control circuit configured to: receive an input current signal, apply a slew current to the input current signal in response to a change in a power setting for the read/write head, and provide an output current signal that is adjusted to a quadratic current slew based on the applied slew current, the output current signal generating an output voltage characterized by a linear slew and controlling a movement of the read/write head over the disk.

According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, and a magnetic element provided between the first and the second magnetic poles. The magnetic element includes first to fourth magnetic layers, and first to fifth non-magnetic layers. The fourth magnetic layer includes a first element and at least one of Fe, Co or Ni. The first element including at least one selected from the group consisting of Cr, V, Mn, Ti, N and Sc. The fourth non-magnetic layer including at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag. The fifth non-magnetic layer includes at least one selected from the group consisting of Cu, Au, Cr, Al, V and Ag.