%0 Journal Article
%T Quantum interference-induced stability of repulsively bound pairs of excitations
%A Lea F. Santos
%A Mark I. Dykman
%J Physics
%D 2012
%I arXiv
%R 10.1088/1367-2630/14/9/095019
%X We study the dynamics of two types of pairs of excitations which are bound despite their strong repulsive interaction. One corresponds to doubly occupied sites in one-dimensional Bose-Hubbard systems, the so-called doublons. The other is pairs of neighboring excited spins in anisotropic Heisenberg spin-1/2 chains. We investigate the possibility of decay of the bound pairs due to resonant scattering by a defect or due to collisions of the pairs. We find that the amplitudes of the corresponding transitions are very small. This is a result of destructive quantum interference and explains the stability of the bound pairs.
%U http://arxiv.org/abs/1206.1051v2