Postings for `born': Classical dynamics
of a Linear Chain of AtomsPostings for `born': Classical dynamics
of a Linear Chain of AtomsI notice something strange when I run preset 7, the scattering of a packet by a light mass impurity. After the packet has left the vicinity of the impurity, the graphical trace shows some fine structure which looks like noise. What is it?? -------ADG
It's not noise. As the packet moves through the impurity (and is partially reflected) there will be weak excitation of the high frequency localized impurity mode (which is discussed in preset 8). Because this is a localized mode, the excitation at this frequency remains confined to the neighborhood of the impurity even though the packet (and its reflection) have left the vicinity. Zoom to check the frequency of the ringing, and compare with the frequency of the localized mode (with the same impurity mass) that you get in preset 8. Is there a similar ringing if the impurity mass is set to 10 instead of 0.1? -------RHS