English

Marginal second-order moments do not suffice for entanglement detection

Quantum Physics 2025-06-17 v1

Abstract

The complete knowledge of the global and marginal second-order moments of a quantum state is in general insufficient for entanglement detection. By deriving the conditions on local-unitary (LU) transformations through the second-order moments, we construct pairs of separable and entangled states that are not LU equivalent, contain different amount of entanglement, and are not equivalent under stochastic local operations and classical communication, even though the states share identical global and marginal second-order moments.

Keywords

Cite

@article{arxiv.2506.12406,
  title  = {Marginal second-order moments do not suffice for entanglement detection},
  author = {A. García-Velo and M. Paraschiv and Y. Ban and E. Torrontegui and R. Puebla},
  journal= {arXiv preprint arXiv:2506.12406},
  year   = {2025}
}

Comments

8 pages

R2 v1 2026-07-01T03:17:32.918Z