Zhou, HJ , Chinese Acad Sci, Inst Theoret Phys, Beijing 100080, Peoples R China
部门归属:
[Zhou, HJ; Li, K] Chinese Acad Sci, Inst Theoret Phys, Beijing 100080, Peoples R China
英文摘要:
At low temperature,,; the configurational phase space of a macroscopic complex system (e-g., a spin-glass) of N similar to 10(23) interacting particles may split into an exponential number Omega(s) similar to exp(const x N) of ergodic sub-spaces (thermodynamic states). It is usually assumed that the equilibrium collective behavior of such a system is determined by its ground thermodynamic states of the minimal free-energy density, and that the equilibrium free energies follow the distribution of exponential decay. But actually for some complex systems, the equilibrium free-energy values may follow a Gaussian distribution within an intermediate temperature range, and consequently their equilibrium properties are contributed by excited thermodynamic states. Based on this analysis, the re-weighting parameter y in the cavity approach of spin-glasses is easily understood. Depending on the free-energy distribution, the optimal y can either be equal to or be strictly less than the inverse temperature beta.
Zhou Hai-Jun,Li Kang. Distribution of equilibrium free energies in a thermodynamic system with broken ergodicity[J]. COMMUNICATIONS IN THEORETICAL PHYSICS,2008,49(3):659-664.
