An Alternative Indicator for the Collapse Transition: Autocorrelation Time

In canonical statistical analysis, it is common to employ response quantities such as the specific heat to identify changes in the thermodynamic behavior of finite systems. However, as a consequence of finite-size effects, conventional thermodynamic quantities do not necessarily exhibit clear indications for pronounced thermal activity. By means of Metropolis Monte Carlo simulations of a coarse-grained model for flexible polymers, we investigate how the integrated autocorrelation times of energetic and structural quantities depend on the temperature. We show that, due to critical slowing down, an extremal autocorrelation time can also be considered as an indicator for the so-called collapse transition, which corresponds to a gas-liquid phase transition.