The diamond nitrogen-vacancy (NV) center is an excellent candidate for quantum information processing, whereas entangling separate NV centers is still of great experimental challenge. We propose an one-step conditional phase flip with three NV centers coupled to a whispering-gallery mode cavity by virtue of the Raman transition and smart qubit encoding. As decoherence is much suppressed, our scheme could work for more qubits. The experimental feasibility is justified.
@article{arxiv.1006.0278,
title = {One-step implementation of multi-qubit conditional phase gating with nitrogen-vacancy centers coupled to a high-Q silica microsphere cavity},
author = {Wan-li Yang and Zhang-qi Yin and Zhen-yu Xu and Mang Feng and Jiang-feng Du},
journal= {arXiv preprint arXiv:1006.0278},
year = {2012}
}