  We investigate the tunneling magnetoresistance (TMR) effect using the lattice
models which describe the magnetic tunnel junctions (MTJ). First, taking a
conventional ferromagnetic MTJ as an example, we show that the product of the
local density of states (LDOS) at the center of the barrier traces the TMR
effect qualitatively. The LDOS inside the barrier has the information on the
electrodes and the electron tunneling through the barrier, which enables us to
easily evaluate the tunneling conductance more precisely than the conventional
Julliere's picture. We then apply this method to the MTJs with collinear
ferrimagnets and antiferromagnets. We find that the TMR effect in the
ferrimagnetic and antiferromagnetic MTJs changes depending on the interfacial
magnetic structures originating from the sublattice structure, which can also
be captured by the LDOS. Our findings will reduce the computational cost for
the qualitative evaluation of the TMR effect, and be useful for a broader
search for the materials which work as the TMR devices showing high
performance.
