We present a scheme for the multi-electron Greenberger-Horne-Zeilinger (GHZ) state analyzer, resorting to an interface between the polarization of a probe photon and the spin of an electron in a quantum dot embedded in a microcavity. All the multi-spin GHZ states can be completely discriminated by using single-photon detectors and linear optical elements. Our scheme has some features. First, it is a complete GHZ-state analyzer for multi-electron spin systems. Second, the initial entangled states remain after being identified and they can be used for a successive task. Third, the electron qubits are static and the photons play a role of a medium for information transfer, which has a good application in quantum repeater in which the electron qubits are used to store the information and the photon qubits are used to transfer the information between others.
@article{arxiv.1209.4732,
title = {Complete deterministic multi-electron Greenberger-Horne-Zeilinger state analyzer for quantum communication},
author = {Hai-Rui Wei and Bao-Cang Ren and Mei Zhang and Tao Li and Fu-Guo Deng},
journal= {arXiv preprint arXiv:1209.4732},
year = {2012}
}