Magnetic memory using spin orbit interaction
A magnetic memory includes: a base layer; a magnetization free layer; a barrier layer; and a magnetization reference layer. The magnetization free layer, with which the base layer is covered, has invertible magnetization and is magnetized approximately uniformly. The barrier layer, with which the magnetization free layer is covered, is composed of material different from material of the base layer. The magnetization reference layer is arranged on the barrier layer and has a fixed magnetization. When the magnetization of the magnetization free layer is inverted, a first writing current is made to flow from one end to the other end of the magnetization free layer in an in-plane direction without through the magnetization reference layer.
1. A magnetic memory comprising:
a base layer;
a magnetization free layer formed over the base layer, configured to have invertible magnetization and be magnetized approximately uniformly;
a barrier layer formed over the magnetization free layer; and
a magnetization reference layer formed over the barrier layer and having fixed magnetization,
wherein when the magnetization of the magnetization free layer is inverted, a first writing current is made to flow from one end to the other end of the magnetization free layer in an inplane direction without flowing through the magnetization reference layer,
wherein the magnetization free layer has perpendicular magnetic anisotrophy,
wherein the magnetization free layer has a shape such that the first writing current is inhomogeneously-distributed in the magnetization free layer,
wherein the base layer includes at least one of a Ta film, a Pt film and a Ta/Pt lamination film,
wherein the magnetization free layer includes at least one of a Co film, a Co/Ni lamination film, a Co/Pt lamination film and a CoFeB film,
wherein the barrier layer includes at least one of an Al2O3 film and a MgO film, and
wherein the magnetization reference layer includes at least one of a Co film, a Co/Ni lamination film, a Co/Pt lamination film and a CoFeB film.
2. The magnetic memory according to claim 1 , further comprising:
a first and a second electrodes configured to be arranged at both ends of the base layer,
wherein the first writing current flows from one of the first and the second electrodes to the other of the first and the second electrodes.
3. The magnetic memory according to claim 1 , wherein the magnetization free layer has perpendicular magnetic anisotropy, and
wherein a wiring line is arranged at a position shifted from a position above the magnetization free layer.
4. The magnetic memory according to claim 1 , wherein the magnetization free layer has perpendicular magnetic anisotropy, and
wherein the magnetization free layer has a region where inversion nucleation easily arises in a part of the magnetization free layer.
5. The magnetic memory according to claim 2 , wherein the first and the second electrodes are asymmetric with respect to the magnetization free layer.