Faithful Qubit Distribution Assisted by One Additional Qubit against Collective Noise
Takashi Yamamoto, Junichi Shimamura, Şahin Kaya Özdemir, Masato Koashi, N. Imoto · Physical Review Letters · 2005
We propose a distribution scheme of polarization states of a single photon over a collective-noise channel. By adding one extra photon with a fixed polarization, we can protect the state against collective noise via a parity-check measurement and postselection. While the scheme succeeds only probabilistically, it is simpler and more flexible than the schemes utilizing decoherence-free subspace. An application to the Bennett-Brassard 1984 protocol through a collective-noise channel, which is robust to the Trojan horse attack, is also given.