Jump rate and jump lengths in periodic systems with memory

The jump rate and the jump-length probability distribution (JLPD) are calcu lated in a periodic potential with exponentially decaying memory friction, solving the generalized Langevin equation (GLE) by the matrix-continued-fra ction method (MCFM). It is shown that the jump rate, as a function of the m emory decay parameter, presents a turnover point; below the turnover a sign ificant percentage of long jumps appears even at sufficiently high static f riction, where long jumps are strictly forbidden in the absence of memory. (C) 2001 Elsevier Science BN. All rights reserved.