  We address the following important question: how to distinguish Kitaev models
experimentally realized on small lattices from other non-topological
interacting spin models. Based on symmetry arguments and exact diagonalization,
we show that a particularly characteristic pattern of spin-spin correlations
survives despite finite size, open boundary and thermal effects. The pattern is
robust against small residual perturbing interactions and can be utilized to
distinguish the Kitaev interactions from other interactions such as
antiferromagnetic Heisenberg interactions. The effect of external magnetic
field is also considered and found to be not critical.
