Patent ID: 7864564

Claim:
A nonvolatile memory device comprising: a plurality of word lines; a plurality of bit lines arranged in an intersectional direction with respect to a direction of the word lines; and a plurality of memory cells each arranged at an intersection of the word line and the bit line, each said memory cell including a pinned magnetic layer having a magnetization direction fixed in a predetermined direction, a free magnetic layer having a magnetization direction that is parallel or antiparallel with respect to the magnetization direction of said pinned magnetic layer, a magneto-resistance element having a tunneling layer arranged between said pinned magnetic layer and said free magnetic layer, and a transistor connected in series with said magneto-resistance element and having a gate connected with the corresponding word line; the magnetization direction of the free magnetic layer being switched by using spin injection mechanism of supplying an electric current to the corresponding memory cell, duration of supplying the electric current to a selected memory cell for reading data from the selected memory cell being shorter than 10 nanoseconds, and duration of supplying the electric current to the selected memory cell for writing data to the selected memory cell being longer than 10 nanoseconds, wherein the electric current supplied during a write operation is set longer than a time constant of a temperature increase, and the electric current supplied during a read operation is set shorter than the time constant of the temperature increase.