  In this study, we propose a spin-star model for spin-(1/2) particles in order
to examine the coherence dynamics of a quantum neural network (QNN) unit. Since
quantum computing paradigm promises advantages over their classical
counterparts, quantum versions of neural networks can be examined in this
context. We focus on quantum coherence as a natural resource for quantum
computing and investigate the central spin coherence of a spin star model in
the time domain in a dissipative environment. More particularly, we investigate
the extend to which the central spin coherence time would be prolonged under
specific parameters and spin-coupling Hamiltonians in a Markov environment. We
show that Ising-type spin coupling is not desirable since it rapidly diminishes
the coherence time in a dissipative environment.
