Five-wave-packet quantum error correction based on continuous-variable cluster entanglement

TL;DR

This paper experimentally demonstrates a five-wave-packet quantum error correction scheme using continuous-variable cluster entanglement, protecting quantum information against stochastic errors in quantum communication.

Contribution

It implements a novel five-wave-packet error correction code based on continuous-variable cluster states, with immunity to errors in two channels and fidelity surpassing classical limits.

Findings

Successfully corrects stochastic errors in a single channel

Fidelities of output states exceed classical limits

Input information is distributed over three channels for error immunity

Abstract

Quantum error correction protects the quantum state against noise and decoherence in quantum communication and quantum computation, which enables one to perform fault-torrent quantum information processing. We experimentally demonstrate a quantum error correction scheme with a five-wave-packet code against a single stochastic error, the original theoretical model of which is firstly proposed by S. L. Braunstein and T. A. Walker. Five submodes of a continuous variable cluster entangled state of light are used for five encoding channels. Especially, in our encoding scheme the information of the input state is only distributed on three of the five channels and thus any error appearing in the remained two channels never affects the output state, i.e. the output quantum state is immune from the error in the two channels. The stochastic error on a single channel is corrected for both vacuum and squeezed input states and the achieved fidelities of the output states are beyond the corresponding classical limit.