Detection of multipartite entanglement with two-body correlations

Witnessing Multipartite Entanglement by Detecting Asymmetry

The characterization of quantum coherence in the context of quantum information theory and its interplay with quantum correlations is currently subject of intense study. Coherence in a Hamiltonian eigenbasis yields asymmetry, the ability of a quantum system to break a dynamical symmetry generated by the Hamiltonian. We here propose an experimental strategy to witness multipartite entanglement i...

Title Genuine multipartite entanglement without multipartite correlations

Monogamy and Polygamy of Entanglement in Multipartite Quantum Systems

One distinct property of quantum entanglement from other classical correlations is that multipartite entanglements cannot be freely shared among the parties: If two parties in a multi-party system share a maximally entangled state, then they cannot share any entanglement with the rest. This is known as monogamy of entanglement (MoE) [1], which is a key ingredient for secure quantum cryptography...

Detecting genuine multipartite entanglement of pure states with bipartite correlations

Correlation loss and multipartite entanglement across a black hole horizon

We investigate the Hawking effect on entangled fields. By considering a scalar field which is in a two-mode squeezed state from the point of view of freely falling (Kruskal) observers crossing the horizon of a Schwarzschild black hole, we study the degradation of quantum and classical correlations in the state from the perspective of Schwarzschild observers confined outside the horizon. Due to ...