Magnetoresistance effect element and magnetic memory device
A magnetoresistance effect element ( 100 ) includes a heavy metal layer ( 11 ) that includes a heavy metal and that is formed to extend in a first direction, a recording layer ( 12 ) that includes a ferromagnetic material and that is provided adjacent to the heavy metal layer ( 11 ), a barrier layer ( 13 ) that includes an insulating material and that is provided on the recording layer ( 12 ) with being adjacent to a surface of the recording layer ( 12 ) opposite to the heavy metal layer ( 11 ), and a reference layer ( 14 ) that includes a ferromagnetic material and that is provided adjacent to a surface of the barrier layer ( 13 ), the surface being opposite to the recording layer ( 12 ). The direction of the magnetization of the reference layer ( 14 ) has a component substantially fixed in the first direction, and the direction of the magnetization of the recording layer ( 12 ) has a component variable in the first direction. A current having a direction same as the first direction is introduced to the heavy metal layer ( 11 ) to thereby enable the magnetization of the recording layer ( 12 ) to be inverted.
1. A magnetoresistance effect element comprising:
a heavy metal layer that comprises a heavy metal and that is formed to extend in a first direction;
a recording layer that comprises a ferromagnetic material and that is provided adjacent to the heavy metal layer;
a barrier layer that comprises an insulating material and that is provided on the recording layer with being adjacent to a surface of the recording layer, the surface being opposite to the heavy metal layer;
a reference layer that comprises a ferromagnetic material and that is provided adjacent to a surface of the barrier layer, the surface being opposite to the recording layer;
a first terminal connected to one end of the heavy metal layer;
a second terminal connected to the other end of the heavy metal layer; and
a third terminal connected to the reference layer,
wherein
a direction of magnetization of the reference layer includes a component substantially fixed in the first direction,
a direction of magnetization of the recording layer includes a component variable in the first direction, and
a current having a direction same as the first direction is introduced to the heavy metal layer to enable the magnetization of the recording layer to be inverted.
2. The magnetoresistance effect element according to claim 1 , wherein the magnetization of the recording layer is inverted by a vertical magnetic field that is applied to the recording layer by introducing a current to the heavy metal layer.
3. The magnetoresistance effect element according to claim 1 , wherein a pulse width of the current introduced to the heavy metal layer is less than 10 nanoseconds.
4. The magnetoresistance effect element according to claim 1 , wherein a magnetization easy axis of the recording layer is directed to a direction within ±25 degrees relative to the first direction.
5. The magnetoresistance effect element according to claim 1 , wherein the recording layer is formed to be substantially two-fold symmetric in a layer surface and a longitudinal direction thereof includes a component in the first direction.
6. A magnetoresistance effect element comprising:
a heavy metal layer that comprises a heavy metal and that is formed to extend in a first direction;
a recording layer that comprises a ferromagnetic material and that is provided adjacent to the heavy metal layer;
a barrier layer that comprises an insulating material and that is provided on the recording layer with being adjacent to a surface of the recording layer, the surface being opposite to the heavy metal layer;
a reference layer that comprises a ferromagnetic material and that is provided adjacent to a surface of the barrier layer, the surface being opposite to the recording layer; and
an auxiliary magnetic layer that comprises magnetization in a direction perpendicular to a layer surface of the recording layer,
wherein
a direction of magnetization of the reference layer includes a component substantially fixed in the first direction,
a direction of magnetization of the recording layer includes a component variable in the first direction, and
a current having a direction same as the first direction is introduced to the heavy metal layer to enable the magnetization of the recording layer to be inverted.
7. A magnetoresistance effect element comprising:
a heavy metal layer that comprises a heavy metal and that is formed to extend in a first direction;
a recording layer that comprises a ferromagnetic material and that is provided adjacent to the heavy metal layer;
a barrier layer that comprises an insulating material and that is provided on the recording layer with being adjacent to a surface of the recording layer, the surface being opposite to the heavy metal layer; and
a reference layer that comprises a ferromagnetic material and that is provided adjacent to a surface of the barrier layer, the surface being opposite to the recording layer,
wherein
a direction of magnetization of the reference layer includes a component substantially fixed in the first direction,
a direction of magnetization of the recording layer includes a component variable in the first direction,
a current having a direction same as the first direction is introduced to the heavy metal layer to enable the magnetization of the recording layer to be inverted, and
the recording layer is singly arranged on each of upper and lower surfaces of the heavy metal layer.
8. A magnetoresistance effect element comprising:
a heavy metal layer that comprises a heavy metal and that is formed to extend in a first direction;
a recording layer that comprises a ferromagnetic material and that is provided adjacent to the heavy metal layer;
a barrier layer that comprises an insulating material and that is provided on the recording layer with being adjacent to a surface of the recording layer, the surface being opposite to the heavy metal layer; and
a reference layer that comprises a ferromagnetic material and that is provided adjacent to a surface of the barrier layer, the surface being opposite to the recording layer,
wherein
a direction of magnetization of the reference layer includes a component substantial fixed in the first direction,
a direction of magnetization of the recording layer includes a component variable in the first direction,
a current having a direction same as the first direction is introduced to the heavy metal layer to enable the magnetization of the recording layer to be inverted, and
the recording layer comprises a plurality of regions where a magnetization easy axis is directed to a different direction.
9. The magnetoresistance effect element according to claim 1 , wherein
the recording layer comprises CoFeB or FeB, and
the barrier layer comprises MgO.
10. The magnetoresistance effect element according to claim 1 , wherein the recording layer comprises CoFeB and a thickness of the recording layer is more than 1.4 nm.
11. The magnetoresistance effect element according to claim 3 , wherein the pulse width of the current introduced to the heavy metal layer is 0.3 nanoseconds or more and less than 1.2 nanoseconds.
12. The magnetoresistance effect element according to claim 4 , wherein the magnetization easy axis of the recording layer is directed to a direction at ±3 degrees or more and ±25 degrees or less relative to the first direction.
13. A magnetic memory device comprising:
the magnetoresistance effect element according to claim 1 ;
write means that writes data in the magnetoresistance effect element by applying a write current to the magnetoresistance effect element to a direction including a component in the first direction; and
read means that reads the data written in the magnetoresistance effect element by determining a resistance between the heavy metal layer and the reference layer.