Sensitivity of Kinetic Monte Carlo Trajectories to the Entropy Source

Kinetic Monte Carlo (KMC) simulations are widely used to model non-equilibrium processes in which system evolution is governed by sequences of activated events. In such simulations, system evolution depends on the ordered sequence of events selected from a dynamically constructed event catalogue using random numbers at each step. In this work, we investigate the sensitivity of rare event KMC simulations to the underlying source of randomness. We then perform a controlled comparison of quantum and pseudo-random numbers in KMC simulations of two-dimensional hexagonal boron nitride growth, using identical physical models and a fixed deposition flux. Despite similar growth morphologies, the two entropy sources produce distinct growth trajectories, manifested in delayed growth and a systematically different entropy evolution of the system. These results demonstrate that the choice of entropy source can influence trajectory-level behavior in rare event KMC simulations.