Retrieval of phase memory in two independent atomic ensembles by Raman process Cheng-Ling Bian, Li-Qing Chen, Guo-Wan Zhang, Z. Y. Ou and Weiping Zhang EPL, 97 3 (2012) 34005 Published online: 31 January 2012 DOI: 10.1209/0295-5075/97/34005