Microcanonical entropy inflection points: Key to systematic understanding of transitions in finite systems

摘要

We introduce a systematic classification method for the analogs of phasetransitions in finite systems. This completely general analysis, which isapplicable to any physical system and extends towards the thermodynamic limit,is based on the microcanonical entropy and its energetic derivative, theinverse caloric temperature. Inflection points of this quantity signalcooperative activity and thus serve as distinct indicators of transitions. Wedemonstrate the power of this method through application to the long-standingproblem of liquid-solid transitions in elastic, flexible homopolymers.