Efficient scheme for hybrid teleportation via entangled coherent states in circuit quantum electrodynamics.

Jaewoo Joo,Eran Ginossar

doi:10.1038/srep26338

Abstract

We propose a deterministic scheme for teleporting an unknown qubit state through continuous-variable entangled states in superconducting circuits. The qubit is a superconducting two-level system and the bipartite quantum channel is a microwave photonic entangled coherent state between two cavities. A Bell-type measurement performed on the hybrid state of solid and photonic states transfers a discrete-variable unknown electronic state to a continuous-variable photonic cat state in a cavity mode. In order to facilitate the implementation of such complex protocols we propose a design for reducing the self-Kerr nonlinearity in the cavity. The teleporation scheme enables quantum information processing operations with circuit-QED based on entangled coherent states. These include state verification and single-qubit operations with entangled coherent states. These are shown to be experimentally feasible with the state of the art superconducting circuits.

Highlights

State (ECS), |ψ〉=|α〉|α〉+|−α〉|−α〉, naturally fits to be a channel state for CV teleportation
In contrast to discrete variables (DVs)- and CV-only teleportations, we find that the teleportation fidelity depends on the amount of decoherence and on the amplitude size of the ECS channel state
Before we present the details of hybrid teleportation, let us discuss one of the major barriers to realising complex protocols involving ECS, namely the ‘self-Kerr effect’

Summary

Introduction

State (ECS), |ψ〉=|α〉|α〉+|−α〉|−α〉, naturally fits to be a channel state for CV teleportation. DV-CV hybrid teleportation is an alternative for DV-qubit teleportation and advantageous for practical quantum information processing in solid-state and cavity-QED systems[53,54,55,56]. These recent developments will lead innovative tools for quantum computing using hybrid single- and two-qubit gates[57,58,59]. The scheme is physically hybrid in the sense that it teleports quantum information from a solid-state qubit to microwave photonic state It is a core building block required for measurement-based quantum computation in superconducting circuits[5,6,28,60]. The schemes of verification of ECSs and of a single-qubit gate on ECSs are proposed toward universal hybrid quantum computing in circuit-QED

Methods

Results

Conclusion