Domain Wall Memories (DWM)
Domain wall memory is a memory that uses magnetic domains introduced in a narrow wire
of ferromagnetic materials. As shown in the figure, pulse current to the lead crossing
the ferromagnetic narrow wire can introduce magnetic domains. Depending on the direction
of magnetizations, logic 1 and 0 can be stored. For reading, current is applied to the
narrow ferromagnetic wire, which drives the magnetic domains to the direction of the
current. If the current is highly spin polarized, magnetic domain will move at a lower
current. The stored information ca be read using a mangetic senser like tunneling
magnetoresistance (TMR).
Fig. 1 Concept of domain wall memory.
This memory has not been realized in practice, but NEC demonstrated the feasibility
of domain wall memory.
