A disk drive apparatus determines a pattern of bits of a data signal applied to a magnetic write transducer of a heat-assisted magnetic recording apparatus. The magnetic write transducer applies a magnetic field to a recording medium in response to the data signal. A laser power signal is applied to a laser that heats the recording medium while the magnetic field is applied. The laser power signal is modulated based on the pattern of bits. The modulation reduces differences between track widths of recorded marks having different elapsed time values and/or increases a signal-to-noise ratio of the recorded marks having different elapsed time values.

In an information recording/playback device adopting multi-value recording, a configuration to limit the size of marks to be recorded on a recording medium only to a predetermined size equal to or smaller than a beam spot size to enable prevention and reduction of crosstalk and crosswrite is implemented. A recording pulse generation unit configured to generate a recording pulse based on a multi-value modulation data, and a data recording unit configured to record the mark on the recording medium on the basis of the recording pulse are included. The data recording unit executes recording processing of setting sizes of all of marks to be recorded on the recording medium to a size equal to or smaller than a spot size at a half (½) level of a maximum value (Pmax) of a two-dimensional light intensity distribution (power profile) of a beam spot, and executes data recording processing of forming recording regions in modes having different densities of recording marks according to the levels of the multi-value modulation data.

In an information recording/playback device adopting multi-value recording, a configuration to limit the size of marks to be recorded on a recording medium only to a predetermined size equal to or smaller than a beam spot size to enable prevention and reduction of crosstalk and crosswrite is implemented. A recording pulse generation unit configured to generate a recording pulse based on a multi-value modulation data, and a data recording unit configured to record the mark on the recording medium on the basis of the recording pulse are included. The data recording unit executes recording processing of setting sizes of all of marks to be recorded on the recording medium to a size equal to or smaller than a spot size at a half (½) level of a maximum value (Pmax) of a two-dimensional light intensity distribution (power profile) of a beam spot, and executes data recording processing of forming recording regions in modes having different densities of recording marks according to the levels of the multi-value modulation data.

According to one embodiment, a magnetic disk device includes: a disk; a head including a main magnetic pole, a write shield that faces the main magnetic pole in a first direction and is separated from the main magnetic pole by a gap, a first assist element that is disposed in the gap and a second assist element that is disposed in the gap and is positioned relative to the first assist element in a second direction intersecting the first direction; and a controller configured to: cause a first assist energy from the first assist element to be applied to the disk and affect a coercive force of the disk; and cause a second assist energy from the second assist element to be applied to the disk and affect a coercive force of the disk, wherein the first assist energy is different from the second assist energy.

According to one embodiment, a magnetic disk device includes a disk having a first area, and a second area to which data is temporary written, a head including a write head which writes data to the disk, and an assisting element which generates energy which improves write performance of the write head, and a controller which writes data to the first area by supplying energy having a first value to the assisting element, and writes data to the second area by supplying energy having a second value different from the first value to the assisting element.

Two or more different elapsed time values are determined between transitions of a data signal applied to a magnetic write transducer of a heat-assisted magnetic recording apparatus. Two or more different power values of the laser are respectively associated with the two or more different elapsed time values. The two or more different power levels are selected to reduce differences between track widths of recorded marks having the two or more different elapsed time values.

A semiconductor storage device comprises a plurality of memory cells arranged in a matrix. Each of the memory cells includes: a semiconductor storage element including a silicon carbide substrate and a silicon carbide film on a first surface of the silicon carbide substrate; a lower electrode on a second surface facing away from the first surface of the silicon carbide substrate; and an upper electrode on at least part of a surface of the silicon carbide film, the surface facing away from another surface of the silicon carbide film in contact with the silicon carbide substrate. Each memory cell includes at least one basal plane dislocation formed at at least part of the semiconductor storage element.

A semiconductor storage device comprises a plurality of memory cells arranged in a matrix. Each of the memory cells includes: a semiconductor storage element including a silicon carbide substrate and a silicon carbide film on a first surface of the silicon carbide substrate; a lower electrode on a second surface facing away from the first surface of the silicon carbide substrate; and an upper electrode on at least part of a surface of the silicon carbide film, the surface facing away from another surface of the silicon carbide film in contact with the silicon carbide substrate. Each memory cell includes at least one basal plane dislocation formed at at least part of the semiconductor storage element.

A data storage device is disclosed comprising a non-energy assist (NEA) head configured to access a first disk surface, and an energy assist (EA) head configured to access a second disk surface. The data storage device further comprises control circuitry configured to write data to the first disk surface, and migrate at least part of the data to the second disk surface.

According to one embodiment, a magnetic disk device includes: a disk; a head including a main magnetic pole, a write shield that faces the main magnetic pole in a first direction and is separated from the main magnetic pole by a gap, a first assist element that is disposed in the gap and a second assist element that is disposed in the gap and is positioned relative to the first assist element in a second direction intersecting the first direction; and a controller configured to: cause a first assist energy from the first assist element to be applied to the disk and affect a coercive force of the disk; and cause a second assist energy from the second assist element to be applied to the disk and affect a coercive force of the disk, wherein the first assist energy is different from the second assist energy.