Energy dependence of the entanglement entropy of composite boson (quasiboson) systems

Bipartite composite boson (quasiboson) systems, which admit realization in terms of deformed oscillators, were considered in our previous paper from the viewpoint of entanglement characteristics. These characteristics, including entanglement entropy and purity, were expressed through the relevant deformation parameter for different quasibosonic states. On the other hand, it is of interest to present the entanglement entropy and likewise the purity as function of energy for those states. In this work, the corresponding dependencies are found for different states of composite bosons realized by deformed oscillators and, for comparison, also for the hydrogen atom viewed as composite boson. The obtained results are expressed graphically and their implications discussed.