Abstract: A magnetic storage device is provided which has significantly reduced power consumption. The magnetic storage device includes: a yoke which is arranged so as to cover part of a line extending in an arbitrary direction; and a magneto-resistive element which is arranged near the line and is capable of writing information using a field occurring from the line. The magnetic storage device is set to satisfy the equation Iw?a·R+b, where Iw is the write current necessary for the line, R is the magnetoresistance of the yoke, a (mA·H)=7.5E?11, and b (mA)=0.1.

Abstract: In the magnetic storage device, magnetization characteristics during write cycles are homogenized, and write cycles are carried out efficiently. In the magnetic storage device, the soft magnetic body is formed so as to cover the line either totally or partially, and the anti-ferromagnetic layer is formed on the outer surface of this soft magnetic body. Furthermore, the magneto-resistive element is disposed in the vicinity of the line. Suppose the case where the exchange coupling energy at the interface between the soft magnetic body and the anti-ferromagnetic layer is J (erg/cm2), the saturation magnetization of the soft magnetic body is Ms (emu/cc), and the coercive force of the soft magnetic body is Hc (Oe). Then, the thickness t (cm) of the soft magnetic body is selected to be such that t<J/(Hc·Ms).

Abstract: The direction of magnetization of a reading ferromagnetic material 5R forming a spin filter when reading is the same as that of a pinned layer 1. In this case, a torque that works on the spin of a free layer 3 due to a spin polarized current becomes “zero.” When the element size is made small so as to improve the integration degree of the magnetic memory, according to the scaling law, the writing current can be made small. In the present invention, the resistance to the spin injection magnetization reversal due to a reading current is high, so that the magnitude of the writing current can be lowered.

Abstract: An optical waveguide is formed on a substrate 11 by the steps of (1) forming an lower clad layer 12, core layer 13, metal mask layer 14 and a photoresist layer 15, (2) patterning the photoresist layer 15 by using a photomask 16, (3) etching and patterning the metal mask layer 14 wider than a core of required width using the patterned photoresist layer 15, (4) removing the photoresist layer and the metal mask layer 14 after patterning the core layer 13 by using the patterned metal mask layer 14 to form core 13a, (5) forming an upper clad layer 17 on the lower clad layer 12 so as to bury the patterned core 13a.