Trade-off between Squashed Entanglement and Concurrence in Bipartite Quantum States

In this article, we investigate the unitary dynamics of squashed entanglement and concurrence measures in Werner state and maximally entangled mixed states (MEMS) under two different Hamiltonians. The aim of the present study is twofold. The first part of the study deals with the dynamics under Heisenberg Hamiltonian and the second part deals under bi-linear bi-quadratic Hamiltonian which is the extension of the first Hamiltonian. In both parts, we investigate the dynamical trade-off and equilibrium points for squashed entanglement and concurrence. During the study, we also found the results of entanglement sudden death (ESD) with Heisenberg Hamiltonian in Werner state under concurrence measure. In the second part, we investigate the special result for the bi-linear bi-quadratic Hamiltonian which does not disturb squashed entanglement and concurrence in both the states and exhibits the robust character for both of the states.