Measuring Renyi Entanglement Entropies of the t-deformed Fredkin Spin Chain via Monte Carlo Simulation

Entanglement entropies have proved useful in characterizing the ground states of quantum many-body systems. We study the Rényi entanglement entropy of the t-deformed Fredkin model, a one-parameter family of spin-half chains with constrained dynamics enforced by unusual three-site interactions. Previous analytical work has established that how the entanglement entropy scales with system size depends on t, with distinct low-t and high-t regimes separated by the critical tuning at t=1. We present numerical results from Monte Carlo simulation to further elucidate the nature of this transition.