Brownian pump induced by the phase difference between the potential and the entropic barrier Xin-tong Zheng, Jian-chun Wu, Bao-quan Ai and Feng-guo Li Eur. Phys. J. B, 86 11 (2013) 479 Published online: 20 November 2013 DOI: 10.1140/epjb/e2013-40862-y