  We investigate the effect of a finite temperature on the behavior of logic
circuits based on the principle of Quantum Cellular Automata (QCA) and of
ground state computation. In particular, we focus on the error probability for
a wire of QCA cells that propagates a logic state. A numerical model and an
analytical, more approximate, model are presented for the evaluation of the
partition function of such a system and, consequently, of the desired
probabilities. We compare the results of the two models, assessing the limits
of validity of the analytical approach, and provide estimates for the maximum
operating temperature.
