The thermodynamic properties of Reissner-Nordstrom-de sitter black hole with quintessence

Recently, numerous investigations have revealed that AdS black holes exhibit fundamental characteristics similar to those of ordinary thermodynamic systems. The thermodynamic properties of multi-horizon spacetimes with different Hawking temperatures have garnered significant attention. In this paper, we regard the Reissner-Nordstrom-de Sitter black hole with quintessence (RN-dSQ black hole) as an equivalent thermodynamic system and firstly provide the effective thermodynamic quantities of RN-dSQ spacetime. Then, the heat capacity of the RN-dSQ spacetime with coexistence of two horizons described by effective thermodynamic quantities is discussed. The results indicate that for the RN-dSQ black hole system with the coexistence of two horizons, the variation curves of the heat capacity with the effective temperature and ratio of two horizons possess characteristics similar to the paramagnetic system. Additionally, the RN-dSQ spacetime can be regard as an ordinary two-level quantum system in which the particles locate at different horizons with different energies. Assuming that the heat capacity of RN-dSQ spacetime is primarily contributed by microscopic particles located between the two horizons. By comparison, the number of microscopic particles in RN-dSQ spacetime is obtained, which just reflects the quantum properties of dS spacetime.