2008/02/29 by A. Ramirez-Hernandez, Abelardo Ramírez-Hernández, Hernán Larralde +2 · 68 citations
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Entropy (arrow of time) #Extended irreversible thermodynamics #Internal energy #Laws of thermodynamics #Non-equilibrium thermodynamics #Physics #Quantum many-body systems #Second law of thermodynamics #Specific heat #Statistical Mechanics and Entropy #Statistical physics #Thermodynamics #Zeroth law of thermodynamics #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevlett.100.120601
published in Physical Review Letters 100(12), 120601 (American Physical Society) · Physical Review Letters, 100, 120601 (2008)
openalex publication_date 2008/03/25 · arxiv created 2008/04/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We show that systems with negative specific heat can violate the zeroth law of thermodynamics. By both numerical simulations and by using exact expressions for free energy and microcanonical entropy, it is shown that if two systems with the same intensive parameters but with negative specific heat are thermally coupled, they undergo a process in which the total entropy increases irreversibly. The final equilibrium is such that two phases appear; that is, the subsystems have different magnetizations and internal energies at temperatures which are equal in both systems, but that can be different from the initial temperature.