1206.1051 (Lea F. Santos)

Quantum interference as the cause of stability of repulsively bound
pairs of excitations    [PDF]

Lea F. Santos

We study the dynamics of two types of repulsively bound pairs of excitations: sites doubly occupied by atoms in one-dimensional Bose-Hubbard models, the so-called doublons, and pairs of neighboring up-spins in antiferromagnetic spin-1/2 Heisenberg chains. We show analytically that the pairs can neither split nor merge into a bound trio of excitations even when these transitions are energetically favorable. The cause for such stability is a destructive quantum interference.

View original: http://arxiv.org/abs/1206.1051