Entanglement entropy of impenetrable bosons in 1D: Effects of block length and boundaries

<div>The effects of block length and boundary conditions on the entanglement entropy of two impenetrable bosons in separate spatial partitions of finite extent are studied in this paper. The von Neumann and Rényi entropies decreased monotonically as the lengths of the block and environment become more and more unequal. Also, the system with periodic boundary conditions possesses a larger entanglement entropy than that with open boundaries.</div>