Regular Article

Guaranteed emergence of genuine entanglement in 3-qubit evolving systems

Instituto de Fsica, Universidad Nacional Autónoma de México, Apartado Postal 20-364, Ciudad de México, Mexico

^a e-mail: andreavh@fisica.unam.mx

Received: 22 May 2019
Received in final form: 14 September 2019
Published online: 26 November 2019

Abstract

Multipartite entanglement has been shown to be of particular relevance for a better understanding and exploitation of the dynamics and flow of entanglement in multiparty systems. This calls for analysis aimed at identifying the appropriate processes that guarantee the emergence of multipartite entanglement in a wide range of scenarios. Here we carry on such analysis considering a system of two initially entangled qubits, one of which is let to interact with a third qubit according to an arbitrary unitary evolution. We establish necessary and sufficient conditions on the corresponding Kraus operators, to discern whether the evolved state pertains to either one of the classes of 3-qubit pure states that exhibit some kind of entanglement, namely biseparable, W-, and GHZ- genuine entangled classes. Our results provide a classification of the Kraus operators according to their capacity of producing 3-qubit entanglement, and pave the way for extending the analysis to larger systems and determining the particular interactions that must be implemented in order to create, enhance and distribute entanglement in a specific manner.