Robust photonic entanglement distribution via state-independent encoding onto decoherence-free subspace

TL;DR

This paper demonstrates an experimental scheme for distributing entangled photons robustly over fiber channels by encoding into a decoherence-free subspace, showing high fidelity and robustness against reference frame issues, applicable to multipartite entanglement.

Contribution

The paper introduces a state-independent encoding scheme into a decoherence-free subspace for robust entanglement distribution, applicable to multipartite quantum systems.

Findings

High-fidelity entanglement distribution over fiber channels

Robustness against reference frame fragility

Applicability to multipartite entanglement

Abstract

Efficient and faithful implementation of quantum information tasks, e.g., quantum computing, quantum communication and quantum metrology, requires robust and state-independent decoherence-suppressing measures to protect quantum information carriers. Here we present an experimental demonstration of a robust distribution scheme in which one photon of an entangled photon pair is successfully encoded into and decoded from a decoherence-free subspace (DFS) by a state-independent scheme. We achieved a high-fidelity distribution of the entangled state over fibre communication channel, and also demonstrated that the scheme is robust against fragility of the reference frame. The scheme, thanks to its state-independence, is also applicable to multipartite case where the photon to be distributed is entangled with many other photons. Such a universal scheme opens the possibility of robust distribution of quantum information among quantum communication and computing networks.