We obtained exact heat capacities of the quantum compass model on the square
L x L clusters with L=2,3,4,5 using Kernel Polynomial Method and compare them
with heat capacity of a large compass ladder. Intersite correlations found in
the ground state for these systems demonstrate that the quantum compass model
differs from its classical version.Comment: 4 pages, 2 figures, submitted to J. Phys. Conf. Serie