  In this article we revisit the theory of open quantum systems from the
perspective of fermionic baths. Specifically, we concentrate on the dynamics of
a central spin half particle interacting with a spin bath. We have calculated
the exact reduced dynamics of the central spin and constructed the Kraus
operators in relation to that. Further, the exact Lindblad type cannonical
master equation corresponding to the reduced dynamics is constructed. We have
also briefly touch upon the aspect of non-Markovianity from the backdrop of the
reduced dynamics of the central spin.
