  The Kitaev model, defined on a honeycomb lattice, features an exactly
solvable ground state with fractionalized Majorana fermion excitations, which
can potentially form non-Abelian anyons crucial for fault-tolerant topological
quantum computing. Although Majorana fermions are essential for obtaining the
exact ground state, their physical interpretation in terms of spin operators
remains unclear. In this study, we employ a Green's function approach that
maintains SU(2) symmetry to address this issue and explore the model's finite
temperature properties. Our results demonstrate that the computed temperature
dependence of the correlation functions closely approximates the exact values
at zero temperature, confirming the accuracy of our method. We also present
several exact results concerning the spin Green's function and spin-spin
correlation functions that are specific to the Kitaev model.
