English

Quantum dynamics of localized excitations in a symmetric trimer molecule

Mesoscale and Nanoscale Physics 2009-11-11 v2 Other Condensed Matter

Abstract

We study the time evolution of localized (local bond) excitations in a symmetric quantum trimer molecule. We relate the dynamical properties of localized excitations such as their spectral intensity and their temporal evolution (survival probability and tunneling of bosons) to their degree of overlap with quantum tunneling pair states. We report on the existence of degeneracy points in the trimer eigenvalue spectrum for specific values of parameters due to avoided crossings between tunneling pair states and additional states. The tunneling of localized excitations which overlap with these degenerate states is suppressed on all times. As a result local bond excitations may be strongly localized forever, similar to their classical counterparts.

Keywords

Cite

@article{arxiv.cond-mat/0507631,
  title  = {Quantum dynamics of localized excitations in a symmetric trimer molecule},
  author = {R. A. Pinto and S. Flach},
  journal= {arXiv preprint arXiv:cond-mat/0507631},
  year   = {2009}
}

Comments

9 pages, 12 figures. Improved version with more discussions. Some figures were replaced for better understanding. Accepted in Phys. Rev. A