Data storage device and associated method for writing data to, and reading data from an unpatterned magnetic layer
View Patent ↗A data storage device includes a unpatterned magnetic film having data regions in which to store data. A track is disposed in proximity to the magnetic film, such that the track selectively defines a shiftable magnetic domain wall. In order to select a data bit that is stored in one of the data regions of the magnetic film, a fringing field of the magnetic domain wall in the track is used to selectively change a direction of a magnetic moment in the data region.
1. A data storage device comprising:
an unpatterned magnetic film comprising data regions or storing data;
a track disposed in proximity to the magnetic film, wherein the track selectively defines a shiftable magnetic domain wall; and
wherein a data bit is selectively stored in one of the data regions of the magnetic film, using a fringing field of the magnetic domain wall in the track to selectively change a direction of a magnetic moment in the data region.
2. The data storage device of claim 1 , wherein the domain wall is moved in a direction of charge carriers along the track.
3. The data storage device of claim 1 , wherein the domain wall is moved in an opposite direction at charge carriers along the track.
4. The data storage device of claim 1 , further comprising at least one additional track that is disposed in proximity to the magnetic film.
5. The data storage device of claim 4 , wherein the track and the additional track are disposed on opposite sides of the magnetic film.
6. The data storage device of claim 4 , wherein the data regions are selectively written by using a combination of fringing fields from domain walls in the track and the additional track.
7. The data storage device of claim 6 , further comprising a reading device for reading the data regions.
8. The data storage device of claim 7 , wherein the reading device comprises a magnetoresistive sensor.
9. The data storage device of claim 7 , wherein the reading device comprises a magnetic tunnel junction device.
10. The data storage device of claim 9 , wherein the magnetic tunnel junction device is disposed between the magnetic film and the track on one side of the magnetic film.
11. The data storage device of claim 10 , wherein a magnetic tunnel junction device is disposed between the magnetic film and the track.
12. The data storage device of claim 10 , wherein the reading device further comprises an additional magnetic tunnel junction device.
13. The data storage device of claim 12 , wherein the magnetic tunnel junction device is disposed between the magnetic film and the track on a first side of the magnetic film; and
wherein the additional magnetic tunnel junction device is disposed between the magnetic film and the additional track on a second side of the magnetic film.
14. The data storage device of claim 1 , wherein the magnetic film is formed of a single magnetic layer.
15. The data storage device of claim 1 , wherein the magnetic film is formed of a plurality of magnetic layers.
16. The data storage device of claim 15 , wherein the domain wall in a first magnetic layer is moved in a first direction of charge carriers along the track; and
wherein the domain wall in a second magnetic layer is moved in a second direction of charge carriers along the track that is opposite to the first direction.
17. A data storage device comprising:
an unpatterned magnetic film comprising a plurality of data regions for selectively storing data bits;
a writing track disposed in proximity to the magnetic film for defining a shiftable magnetic domain wall; and
wherein a data bit is selectively written in one of the data regions of the magnetic film by shifting the magnetic domain wall in the track along one of two directions.
18. The data storage device of claim 17 , wherein the domain wall is moved in a direction in which charge carriers move along the track.
19. The data storage device of claim 17 , wherein the domain wall is moved in a direction opposite to which charge carriers move along the track.
20. A data storage device comprising:
an unpatterned magnetic film for storing data bits in a plurality of data regions;
an insulation layer that covers at least some of the data regions;
a reading track disposed in proximity to the magnetic film for defining a shiftable magnetic domain wall;
a conductor disposed in proximity to the magnetic film, for passing a reading current; and
wherein a data bit stored in one of the data regions is read by shifting the magnetic domain wall in the track in proximity to the data region in which the data bit is stored, and by measuring a corresponding variation in the reading current that results from the shifting of the magnetic domain wall.