Spin-orbit-torque magnetization rotational element, spin-orbit-torque magnetoresistance effect element, and magnetic memory

A spin-orbit-torque magnetization rotational element, comprising:

• a first ferromagnetic layer having:
• a first end in a first direction;
• a second end in the first direction;
• and
• a narrow width portion whose width in a second direction orthogonal to the first direction is locally narrower between the first end and the second end when viewed in a plan view from a lamination direction of the first ferromagnetic layer;
• and
• a spin-orbit torque wiring with a main constituent element that is a non-magnetic heavy metal or non-magnetic heavy metals, the spin-orbit torque wiring having:
• a first surface that faces the first ferromagnetic layer and spreads along a reference plane orthogonal to the lamination direction;
• a long axis that extends in the first direction when viewed in the plan view;
• a first virtual cross-section which passes through the first end of the first ferromagnetic layer and is orthogonal to the first direction;
• and
• a second virtual cross-section which passes through the second end of the first ferromagnetic layer and is orthogonal to the first direction, an area of the first virtual cross-section being different from an area of the second virtual cross-section.