Magnetic memory devices and methods of controlling domain sizes thereof

A method of controlling a domain size of a magnetic memory device, wherein the magnetic memory device comprises a magnetic track that extends in a first direction and a first electrode that is provided at a biasing point of the magnetic track, and wherein the magnetic track includes a first region between a first end of the magnetic track and the biasing point and a second region between the biasing point and a second end of the magnetic track, the method comprising:

• applying first and second voltages to the first and second ends, respectively, to move a magnetic domain wall, which defines a magnetic domain, in the first direction;
• and
• applying a third voltage to the first electrode to move the magnetic domain wall in the first region with a first velocity and in the second region with a second velocity, the first velocity different from the second velocity.