Tighter monogamy and polygamy relations using Rényi-$α$ entropy

Abstract: We investigate monogamy relations related to the R\'{e}nyi-$\alpha$ entanglement and polygamy relations related to the R\'{e}nyi-$\alpha$ entanglement of assistance. We present new entanglement monogamy relations satisfied by the $\mu$-th power of R\'{e}nyi-$\alpha$ entanglement with $\alpha\in[\sqrt{7}-1)/2,(\sqrt{13}-1)/2]$ for $\mu\geqslant2$, and polygamy relations satisfied by the $\mu$-th power of R\'{e}nyi-$\alpha$ entanglement of assistance with $\alpha\in[\sqrt{7}-1)/2,(\sqrt{13}-1)/2]$ for $0\leq\mu\leq1$. These relations are shown to be tighter than the existing ones.