The interaction between two two-level atoms via photon exchange is simulated. The language of qubits is used with the aim of possible application of this model to the construction of quantum processors based on the interaction of several atoms with unit photons. The study involves a qubit form of the Jaynes-Cummings-Hubbard model with two-photon excitations and its polariton modification, in which any displacement of photons between cavities is associated with a photon absorbed or emitted by an atom. Relaxation is described by the Kossakowski-Lindblad equation for the density matrix of electron and photon states. The relaxation time is obtained as a function of the photon transition probability between atoms and of the amplitude of the photon interaction with an atom. Additionally, the degree of agreement between the density matrices in both models is calculated. An artifact of incomplete relaxation is described in the case of fuzzy qubit semantics, when the description of photons depends on their number.