A writing device can change the direction of the magnetic moment in a magnetic
shift register, thus writing information to the domains or bits in the magnetic
shift register. Associated with each domain wall are large magnetic fringing fields.
The domain wall concentrates the change in magnetism from one direction to another
in a very small space. Depending on the nature of the domain wall, very large dipolar
fringing fields can emanate from the domain wall. This characteristic of magnetic
domains is used to write to the magnetic shift register. When the domain wall is
moved close to another magnetic material, the large fields of the domain wall change
the direction of the magnetic moment in the magnetic material, effectively "writing"
to the magnetic material.
