Rigorous criterion for reentrance in the spin-1/2 Ising-Heisenberg model on diamond-like decorated Bethe lattices

The spin-1/2 Ising-Heisenberg model on diamond-like decorated Bethe lattices is exactly solved with the help of decoration-iteration transformation and exact recursion relations. It is shown that the model under investigation exhibits reentrant phase transitions whenever a sufficiently high coordination number of the underlying Bethe lattice is considered.