Microcanonical Phase Diagram of the BEG and Ising Models  

作　　者：李粮生 郑宁 史庆藩 

机构地区：[1]Science and Technology on Electromagnetic Scattering Laboratory [2]School of Physics,Beijing Institute of Technology

出　　处：《Communications in Theoretical Physics》2012年第9期445-450,共6页理论物理通讯（英文版）

基　　金：Supported by National Natural Science Foundation of China under Grant No.11104013;Excellent Young Scholars Research Fund of Beijing Institute of Technology

摘　　要：The density of states of long-range Blume-Emery-Criffiths （BEG） and short-range lsing models are obtained by using Wang-Landau sampling with adaptive windows in energy and magnetization space. With accurate density of states, we are able to calculate the mierocanonical specific heat of fixed magnetization introduced by Kastner et al. in the regions of positive and negative temperature. The microcanonical phase diagram of the Ising model shows a continuous phase transition at a negative temperature in energy and magnetization plane. However the phase diagram of the long-range model constructed by peaks of the microeanonieal specific heat looks obviously different from the Ising chart.

关 键 词：Wang-Landau sampling negative temperature 

分 类 号：O469[理学—凝聚态物理]