  A periodic network of connected rhombii, mimicking a spintronic device, is
shown to exhibit an intriguing spin selective extreme localization, when
submerged in a uniform out of plane electric field. The topological Aharonov
Casher phase acquired by a travelling spin is seen to induce a complete caging,
triggered at a special strength of the spin orbit coupling, for half odd
integer spins s \ge n\hbar/2, with n odd, sparing the integer spins. The
observation finds exciting experimental parallels in recent literature on
caged, extreme localized modes in analogous photonic lattices. Our results are
exact.
