Separable ellipsoids around multipartite states

Robin Y. Wen, Gilles Parez, Liuke Lyu +2

We show that, in finite dimensions, around any $m$-partite product state ${\rho }_{\mathrm{prod}}={\rho }_1\otimes ...\otimes {\rho }_m$, there exists an ellipsoid of separable states centered around $ρ_{\…