Quantifying reversibility in a phase-separating lattice gas: an analogy with self-assembly

We present dynamic measurements of a lattice gas during phase separation, which we use as an analogy for self-assembly of equilibrium ordered structures. We use two approaches to quantify the degree of 'reversibility' of this process: firstly, we count events in which bonds are made and broken; secondly, we use correlation-response measurements and fluctuation-dissipation ratios to probe reversibility during different time intervals. We show how correlation and response functions can be related directly to microscopic (ir)reversibility and we discuss time-dependence and observable- dependence of these measurements, including the role of fast and slow degrees of freedom during assembly.