Controlling the conductance and current flow through nanostructured magnetic point contacts is a key challenge
for future spintronic devices. This could be achieved by exploiting the Rashba spin-orbit coupling effect induced
by an external gate in the middle of two pinned domain walls at the point contacts. Here, I investigate the electrical
conductance of a half-metallic diluted magnetic semiconductor nanowire with a double point contact exploitable
in switching devices controlled by lateral gate voltage. The coherent quantum interference between forwardand backward-scattered waves in the spin quantum well formed by the double point contact leads to quasibound
states with finite lifetimes. The energetic position of these quasibound states could be adjusted by the lateral
gate voltage so that the incident energy coincides with one of the quasibound energy levels in the spin quantum
well. Conductance calculations in the presence of an applied electric field perpendicular to the nanowire surface
exhibit typical resonant tunneling behavior, where the nanostructure switches to the low-resistance ON state by
tuning the Rashba coupling strength in the range of a few tens of meV nm. This study paves the way for utilizing
the gate-controlled Rashba spin-orbit coupling effect to design and develop practical spintronic devices.