Experimental few-copy multipartite entanglement detection

Experimental detection of multipartite entanglement using witness operators.

We present the experimental detection of genuine multipartite entanglement using entanglement witness operators. To this aim, we introduce a canonical way of constructing and decomposing witness operators so that they can be directly implemented with present technology. We apply this method to three- and four-qubit entangled states of polarized photons, giving experimental evidence that the con...

Title Genuine multipartite entanglement without multipartite correlations

Genuine Multipartite Entanglement without Multipartite Correlations.

Nonclassical correlations between measurement results make entanglement the essence of quantum physics and the main resource for quantum information applications. Surprisingly, there are n-particle states which do not exhibit n-partite correlations at all but still are genuinely n-partite entangled. We introduce a general construction principle for such states, implement them in a multiphoton e...

Detecting multipartite entanglement

Andrew C. Doherty, Pablo A. Parrilo, and Federico M. Spedalieri School of Physical Sciences, University of Queensland, St Lucia, Queensland 4072, Australia Institute for Quantum Information, California Institute of Technology, Pasadena, California 91125, USA Institut für Automatik, ETH Zentrum, CH-8092 Zürich, Switzerland Quantum Computing Technologies Group, Jet Propulsion Laboratory, Pasadena...

Comparability of multipartite entanglement

Due to its numerous important applications[1–5] in the area of quantum information and computation, entanglement has been extensively studied in the past decade. The concept of considering entanglement as a new type of useful resource has been widely accepted. Efforts have been made to quantitatively and qualitatively measure this kind of resource in both bipartite and multipartite cases[6–8]. ...