  We propose a simple model quantum network consisting of diamond-shaped
plaquettes with deterministic distribution of magnetic and non-magnetic atoms
in presence of a uniform external magnetic flux in each plaquette and predict
that such a simple model can be a prospective candidate for spin filter as well
as flux driven spintronic switch. The orientations and the amplitudes of the
substrate magnetic moments play a crucial role in the energy band engineering
of the two spin channels which essentially gives us a control over the spin
transmission leading to a spin filtering effect. The externally tunable
magnetic flux plays an important role in inducing a switch on-switch off effect
for both the spin states indicating the behavior like a spintronic switch. Even
a correlated disorder configuration in the on-site potentials and in the
magnetic moments may lead to disorder-induced spin filtering phenomenon where
one of the spin channel gets entirely blocked leaving the other one
transmitting over the entire allowed energy regime. All these features are
established by evaluating the density of states and the two terminal
transmission probabilities using the transfer-matrix formalism within a
tight-binding framework. Experimental realization of our theoretical study may
be helpful in designing new spintronic devices.
