Work

Experimental measurement of collective nonlinear entanglement witness for two qubits

Year: 2016

Type: article

Abstract: We present a proof-of-principle experiment demonstrating measurement of the collectibility, a nonlinear entanglement witness proposed by \L{}. Rudnicki et al. [Phys. Rev. Lett. 107, 150502 (2011)]. This entanglement witness works for both mixed and pure two-qubit states. In the latter case it can be used to measure entanglement in terms of the negativity. We measured the collectibility for three distinct classes of photonic polarization-encoded two-qubit states, i.e., maximally entangled, separable, and maximally mixed states. We demonstrate that the measurement procedure is feasible and robust against typical experimental shortcomings such as imperfect two-photon indistinguishability.

Source: Physical Review A

DOI: 10.1103/physreva.94.052334

Authors: Karel Lemr, Karol Bartkiewicz, Antonín Černoch

Institutions: Czech Academy of Sciences, FZU - Institute of Physics of the Czech Academy of Sciences, Palacký University Olomouc, Adam Mickiewicz University in Poznań

Language: English

Topic: Quantum Information and Cryptography

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Ministerstvo Školství, Mládeže a Tělovýchovy, Grantová Agentura České Republiky, Narodowe Centrum Nauki

Awards: G350748741, Experimental characterization and applications of quantum-correlated photons, Suppresion of quantum noise using entanglement present in twin beams, G8703027627