Spin switch and magnetic storage element using it

A spin switch comprising:

• a magnetic semiconductor;
• and
• at least one electrode that is in contact with the magnetic semiconductor via an insulator and covers at least a portion of the magnetic semiconductor,
• wherein the magnetic semiconductor comprises a magnetization switching region having a longitudinal direction that orients in a first direction and a peripheral region next to the magnetization switching region, and a total region of the magnetization switching region and the peripheral region has a longitudinal direction that orients in a second direction different from the first direction,
• wherein a change in electric potential of the at least one electrode causes the magnetic semiconductor to make a reversible transition between a ferromagnetic state and a paramagnetic state in the portion covered with the at least one electrode, and
• wherein the transition produces a first state in which both the magnetization switching region and the peripheral region are ferromagnetic and a second state in which the magnetization switching region is ferromagnetic, while the peripheral region is paramagnetic.