We present an economical setup for faithful entanglement sharing against collective noise. It is composed of polarizing beam splitters, half wave plates, polarization independent wavelength division multiplexers, and frequency shifters. An arbitrary qubit error on the polarization state of each photon in a multi-photon system caused by the noisy channel can be rejected, without resorting to additional qubits, fast polarization modulators, and nondestructive quantum nondemolition detectors. Its success probability is in principle 100%, which is independent of the noise parameters, and it can be applied directly in any one-way quantum communication protocol based on entanglement.
@article{arxiv.1010.0498,
title = {Faithful entanglement sharing for quantum communication against collective noise},
author = {Hui-Chong Niu and Bao-Cang Ren and Tie-Jun Wang and Ming Hua and Fu-Guo Deng},
journal= {arXiv preprint arXiv:1010.0498},
year = {2012}
}