Magnetic memory with circuit to supply shift pulse to move a domain wall in a magnetic body
According to one embodiment, a magnetic memory includes a magnetic body with two portions of a first dimension in a first direction which are spaced from each other a second direction and another portion that has a second dimension less than the first dimension in the first direction, which is between the two other portions. A circuit supplies a shift pulse to the magnetic body. The shift pulse includes a first pulse and a second pulse and moves a domain wall in the magnetic body along the second direction. The first pulse has a first pulse width. The second pulse has a second pulse width less than the first pulse width. The second pulse is supplied to the magnetic body after the first pulse.
1. A magnetic memory, comprising:
a magnetic body including:
a first portion that has a first dimension in a first direction,
a second portion that has the first dimension and spaced from the first portion in a second direction, and
a third portion that has a second dimension, which is greater than the first dimension, in the first direction and is between the first portion and the second portion in the second direction; and
a circuit configured to supply a shift pulse to the magnetic body to move a domain wall in the magnetic body along the second direction, wherein
the shift pulse comprises a first pulse and a second pulse,
the first pulse has a first pulse width,
the second pulse has a second pulse width less than the first pulse width,
the second pulse is after the first pulse;
a first current value of the first pulse is equal to or greater than a second current value of the second pulse,
the first pulse has a first polarity, and
the second pulse has a second polarity different from the first polarity.
2. The magnetic memory according to claim 1 , wherein the first current value is greater than the second current value.
3. The magnetic memory according to claim 1 , wherein
the shift pulse further comprises a third pulse before the first pulse, and
the third pulse has a third pulse width less than the first pulse width.
4. The magnetic memory according to claim 1 , wherein
the circuit supplies a first current to the magnetic body in a period between the first pulse and the second pulse, and
the first current has a current value greater than zero but less than a current value of the first pulse.
5. The magnetic memory according to claim 1 , wherein
the magnetic body is on a substrate, and
the second direction is orthogonal to a surface of the substrate.
6. The magnetic memory according to claim 1 , wherein
the magnetic body is on a substrate, and
the second direction is parallel to a surface of the substrate.
7. A magnetic memory device, comprising:
a magnetic body including:
a plurality of first portions that have each a first dimension in a first direction, the first portions being spaced from each other along a second direction intersecting the first direction, and
a plurality of second portions that have each a second dimension in the first direction that is larger than the first dimension, each second portion being between an adjacent pair of first portions in the second direction; and
a circuit configured to supply a shift pulse to move a domain wall in the magnetic body along the second direction, wherein
the shift pulse comprises a first pulse and a second pulse,
the first pulse having a first pulse width,
the second pulse having a second pulse width that is less than the first pulse width,
the first pulse is supplied to the magnetic body before the second pulse is supplied to the magnetic body, and
a first current value of the first pulse is equal to a second current value of the second pulse.
8. The magnetic memory device according to claim 7 , wherein
the shift pulse further comprises a third pulse that is before the first pulse, and
the third pulse has a third pulse width less than the first pulse width.
9. The magnetic memory device according to claim 7 , wherein
the circuit supplies a first current to the magnetic body in a relaxation period between the first pulse and the second pulse, and
the first current has a current value greater than zero but less than a current value of the first pulse.
10. The magnetic memory device according to claim 7 , wherein
the magnetic body is on a substrate, and
the second direction is orthogonal to a surface of the substrate.
11. The magnetic memory device according to claim 7 , wherein
the magnetic body is on a substrate, and
the second direction is parallel to a surface of the substrate.
12. A magnetic memory storage device, comprising:
a plurality of word lines extending in a first direction;
a plurality of bit lines extending in a second direction;
a plurality of magnetic bodies extending in a third direction perpendicular to the first and second directions, each magnetic body extending between a bit line of the plurality of bit lines and a word line of the plurality of word lines and including:
a first portion that has a first dimension,
a second portion that has the first dimension and is spaced from the first portion in the third direction, and
a third portion that has a second dimension and is between the first portion and the second portion in the third direction, the second dimension being greater than the first dimension; and
a circuit configured to supply a shift pulse to the plurality of magnetic bodies via the bit lines and word lines to move a domain wall of a magnetic body of the plurality of magnetic bodies along the third direction, wherein
the shift pulse comprises a first pulse and a second pulse,
the first pulse has a first pulse width,
the second pulse has a second pulse width less than the first pulse width,
the second pulse is after the first pulse,
the first pulse has a first polarity, and
the second pulse has a second polarity different from the first polarity.
13. The magnetic memory storage device according to claim 12 , wherein
the shift pulse further comprises a third pulse before the first pulse, and
the third pulse has a third pulse width less than the first pulse width.