Quantum networks generation based on four-wave mixing
  We present a scheme to realize versatile quantum networks by cascading several four-wave mixing (FWM) processes in warm rubidium vapors. FWM is an efficient $\chi^{(3)}$ nonlinear process, already used as a resource for multimode quantum state generation and which has been proved to be a promising candidate for applications to quantum information processing. We analyze theoretically the multimode output of cascaded FWM systems, derive its independent squeezed modes and show how, with phase controlled homodyne detection and digital post-processing, they can be turned into a versatile source of continuous variable cluster states. 
Yin Cai, Jingliang Feng, Hailong Wang, Giulia Ferrini, Xinye Xu,   Jietai Jing, and Nicolas Treps
quant-ph