Home
For authors
Submission status

Archive
Archive (English)
Current
   Volumes 113-120
   Volumes 93-112
      Volume 112
      Volume 111
      Volume 110
      Volume 109
      Volume 108
      Volume 107
      Volume 106
      Volume 105
      Volume 104
      Volume 103
      Volume 102
      Volume 101
      Volume 100
      Volume 99
      Volume 98
      Volume 97
      Volume 96
      Volume 95
      Volume 94
      Volume 93
Search
VOLUME 94 (2011) | ISSUE 6 | PAGE 494
Propagating vibrational excitations in molecular chains
Abstract
We investigate quantum dynamics of vibrational excitations in one-dimensional (1D) molecular chain. Our model includes nearest neighbor interaction between identical molecular sites and one impurity atom placed in the middle (n=0). We show that upon exciting the impurity site, its excess energy for relatively long for molecular scales time up to 100 ps is not redistributed uniformly among all other degrees of freedom. On the contrary an excitation propagates along the chain, reflected from the chain ends, and quantum interference of these waves yields to recurrence cycles and echo phenomena. For a critical cycle number kc, echo components of the neighboring cycles start to overlap, and eventually for k \gg k_c dynamics looks like chaotic one. The critical cycle number kc depends on the coupling strength 0 \leq C \leq 1 of the impurity site with its neighbors n = \pm 1. kc achieves the maximum for C2 = 1/2. Our results are in qualitative agreement with experimental data on vibrational excitations in various (CH2)n molecular chains, and besides offer a way for loss-free energy transfer between separated in space reaction centers.