We investigate the monogamy relations related to the concurrence and the entanglement of formation. General monogamy inequalities given by the $\ensuremath{\alpha}\text{th}$ power of concurrence and entanglement of formation are presented for N-qubit states. The monogamy relation for entanglement of assistance is also established. Based on these general monogamy relations, the residual entanglement of concurrence and entanglement of formation are studied. Some relations among the residual entanglement, entanglement of assistance, and three tangle are also presented.
Tighter monogamy and polygamy relations using Rényi-α entropy
We investigate monogamy relations related to the Rényi-α entanglement and polygamy relations related to the Rényi-α entanglement of assistance. We present new entanglement monogamy relations satisfied by the μ-th power of Rényi-α entanglement with α∈[7−1)/2,(13−1)/2] for μ⩾2, and polygamy relations satisfied by the μ-th power of Rényi-α entanglement of assistance with α∈[7−1)/2,(13−1)/2] for 0≤μ≤1. These relations are shown to be tighter than the existing ones.