Efficient creation of multipartite entanglement in flux qubits

TL;DR

This paper presents a method to efficiently generate and analyze different types of tripartite entanglement in a system of three coupled superconducting flux qubits, highlighting controllability and stability.

Contribution

It demonstrates the natural, controllable creation of both W and GHZ tripartite entanglement in flux qubits and discusses the effects of measurement fidelity on entanglement detection.

Findings

Tripartite entanglement types identified in eigenstates

Bell inequality violations analyzed in the system

Impact of measurement fidelity on entanglement detection

Abstract

We investigate three superconducting flux qubits coupled in a loop. In this setup, tripartite entanglement can be created in a natural, controllable, and stable way. Both generic kinds of tripartite entanglement -the W type as well as the GHZ type entanglement- can be identified among the eigenstates. We also discuss the violation of Bell inequalities in this system and show the impact of a limited measurement fidelity on the detection of entanglement and quantum nonlocality.