Magnetic storage device

1. A magnetic storage device comprising:

a magnetic member that includes a portion extending in a direction;

a switch element that is a two-terminal element connected in series to the magnetic member, changes to an on state in a case where a voltage equal to or larger than a predetermined value is applied in an off state, maintains the on state in a case where a current equal to or larger than a holding current value continues to flow in the on state, and changes to the off state in a case where the current flowing in the on state becomes smaller than the holding current value;

a shift control circuit configured to supply a shift pulse current to the magnetic member via the switch element to shift a magnetic domain retained in the magnetic member;

a base current control circuit configured to supply a base current equal to or larger than the holding current value to the switch element; and

a controller configured to cause the base current control circuit to supply the base current to the switch element during a predetermined continuous supply period after the switch element changes from the off state to the on state, and cause the shift control circuit to supply the shift pulse current a plurality of times during the continuous supply period.

2. The magnetic storage device according to claim 1 , wherein

the portion of the magnetic member has a cylindrical shape.

3. The magnetic storage device according to claim 2 , wherein

the magnetic member is able to retain a plurality of magnetic domains in a length direction, and moves the retained magnetic domains in response to a current flowing in the length direction.

4. The magnetic storage device according to claim 3 , wherein

the switch element is electrically connected to an end portion of the magnetic member in the length direction.

5. The magnetic storage device according to claim 1 , wherein

the shift pulse current is an amount of current that shifts all of magnetic domains retained in the magnetic member by a length of one magnetic domain.

6. The magnetic storage device according to claim 5 , wherein

the controller supplies the shift pulse current the same number of times as a number of magnetic domains retainable in the magnetic member during the continuous supply period.

7. The magnetic storage device according to claim 5 , wherein

the controller supplies the shift pulse current a smaller number of times than a number of magnetic domains retainable in the magnetic member during the continuous supply period.

8. The magnetic storage device according claim 1 , further comprising:

a readout element that reads a magnetization direction of a magnetic domain retained at a readout position in the magnetic member, wherein

the shift control circuit supplies the shift pulse current for shifting that the magnetic domain retained in the magnetic member in a direction approaching the readout position in a case where the magnetization direction of the magnetic domain retained in the magnetic member is read.

9. The magnetic storage device according to claim 8 , wherein

the readout element is a magnetoresistance effect element.

10. The magnetic storage device according to claim 9 , further comprising:

a readout control circuit configured to supply a current to the readout element and acquire information of a magnetization direction of a magnetic domain read by the readout element, wherein

the controller causes the readout control circuit to acquire information of a magnetization direction read by the readout element every time the shift pulse current is supplied to the magnetic member.

11. The magnetic storage device according to claim 9 , wherein

the magnetoresistance effect element is provided between the switch element and the magnetic member.

12. The magnetic storage device according to claim 11 , wherein

the magnetoresistance effect element is a magnetic tunnel junction (MTJ) element.

13. The magnetic storage device according claim 1 , further comprising:

a write element that writes a magnetic domain in a magnetization direction according to recording information to a write position in the magnetic member, wherein

the shift control circuit supplies the shift pulse current for shifting the magnetic domain retained in the magnetic member in a direction away from the write position in a case where a magnetic domain is written to the magnetic member.

14. The magnetic storage device according to claim 13 , wherein

the write element includes a field line through which a current flows.

15. The magnetic storage device according to claim 14 , wherein

the write element writes a new magnetic domain to the write position by a magnetic field caused by the current flowing through the field line.

16. The magnetic storage device according to claim 15 , further comprising:

a write control circuit configured to supply a current to the write element, wherein

the controller causes the write control circuit to write a magnetic domain in a magnetization direction according to the recording information to the magnetic member every time the shift pulse current is supplied to the magnetic member.

17. The magnetic storage device according to claim 1 , further comprising:

a readout element that reads a magnetization direction of a magnetic domain retained at a readout position in the magnetic member; and

a write element that writes a magnetic domain in a magnetization direction according to recording information to a write position in the magnetic member, wherein

the readout position and the write position are formed at one end portion of the magnetic member, and

the shift control circuit causes the shift pulse current to flow in different directions between a case where a magnetization direction of a magnetic domain retained in the magnetic member is read and a case where a magnetic domain is written to the magnetic member.

18. A magnetic storage device comprising:

a magnetic member that includes a portion extending in a direction;

a switch element that is a two-terminal element connected in series to the magnetic member, changes to an on state in a case where a voltage equal to or larger than a predetermined value is applied in an off state, maintains the on state in a case where a current equal to or larger than a holding current value continues to flow in the on state, and changes to the off state in a case where the current flowing in the on state becomes smaller than the holding current value;

a readout element that reads a magnetization direction of a magnetic domain retained at a readout position in the magnetic member;

a readout control circuit configured to supply a current to the readout element and acquires information of the magnetization direction of the magnetic domain read by the readout element;

a write element that writes a magnetic domain in a magnetization direction according to recording information to a write position in the magnetic member;

a write control circuit configured to supply a current to the write element;

a shift control circuit configured to supply a shift pulse current to the magnetic member via the switch element to shift the magnetic domain retained in the magnetic member;

a base current control circuit configured to supply a base current equal to or larger than the holding current value to the switch element; and

the controller configured to cause the base current control circuit to supply the base current to the switch element during a predetermined continuous supply period after the switch element changes from the off state to the on state, and cause the shift control circuit to supply the shift pulse current a plurality of times during the continuous supply period.