arXiv:1606.05537 · Journal of Physics A Mathematical and Theoretical
Three-qutrit entanglement and simple singularities
Frédéric Holweck, Hamza Jaffali
Abstract
Abstract In this paper, we use singularity theory to study the entanglement nature of pure three-qutrit systems. We first consider the algebraic variety X of separable three-qutrit states within the projective Hilbert space P ( ) = P 26 . Given a quantum pure state ∣ φ 〉 ∈ P ( ) we define the X φ -hypersuface by cutting X with a hyperplane H φ defined by the linear form 〈 φ ∣ (the X φ -hypersurface of X is X ∩ H φ ⊂ X ). We prove that when ∣ φ 〉 ranges over the stochastic local operation and classical communication entanglement classes, the ‘worst’ possible singular X φ -hypersuface with isolated singularities, has a unique singular point of type D 4 .