arXiv:1006.0061 · Physical Review A
Perfect coherent shift of bound pairs in strongly correlated systems
L. Jin, Z. Song
Abstract
In the present work we extend the concept of coherent shift for the extended Bose-Hubbard model and Fermi-Hubbard model. We present two types of local bound pairs (BPs) for the Bose system and one type for the Fermi system. It is shown exactly that the perfect coherent shift can be achieved in such models in the large binding-energy limit. We find that for a Bose on-site BP, the perfect coherent shift condition depends on the nearest-neighbor interaction strength and the momentum of the incident single-particle wave packet, while for the other two types of BPs, it is independent of the initial state in the proposed systems. Numerical simulation of the scattering process between a single particle and a BP in a finite-size system is conducted and the computational results are shown to confirm the analytical investigation.