Implementing Genuine Multi-Qubit Entanglement of Two-Level-System Inside a Superconducting Phase Qubit

TL;DR

This paper demonstrates a method to generate and detect genuine multi-qubit entanglement among two-level systems inside a superconducting phase qubit using the XY model and iSWAP gate, with implications for quantum computing.

Contribution

It introduces a scheme leveraging the phase qubit and XY model to efficiently produce and verify multi-qubit entangled states like W and cluster states.

Findings

Successful proposal for generating multi-qubit entanglement

Efficient detection of entangled states using entanglement witness

Potential application in quantum computation

Abstract

The interaction between a superconducting phase qubit and the two-level systems locating inside the Josephson tunnel barrier is shown to be described by the XY model, which is naturally used to implement the iSWAP gate. With this gate, we propose a scheme to efficiently generate genuine multi-qubit entangled states of such two-level systems, including multipartite W state and cluster states. In particularly, we show that, with the help of the phase qubit, the entanglement witness can be used to efficiently detect the produced genuine multi-qubit entangled states. Furthermore, we analyze that the proposed approach for generating multi-qubit entangled states can be used in a wide class of candidates for quantum computation.