Phase diagrams of bosonic AB_{n} chains
Abstract
The A B _{ N  1} chain is a system that consists of repeating a unit cell with N sites where between the A and B sites there is an energy difference of λ. We considered bosons in these special lattices and took into account the kinetic energy, the local twobody interaction, and the inhomogenous local energy in the Hamiltonian. We found the charge density wave (CDW) and superfluid and Mott insulator phases, and constructed the phase diagram for N = 2 and 3 at the thermodynamic limit. The system exhibited insulator phases for densities ρ = α/ N, with α being an integer. We obtained that superfluid regions separate the insulator phases for densities larger than one. For any N value, we found that for integer densities ρ, the system exhibits ρ + 1 insulator phases, a Mott insulator phase, and ρ CDW phases. For noninteger densities larger than one, several CDW phases appear.
 Publication:

European Physical Journal B
 Pub Date:
 April 2016
 DOI:
 10.1140/epjb/e2016603315
 arXiv:
 arXiv:1509.07486
 Bibcode:
 2016EPJB...89..106C
 Keywords:

 Solid State and Materials;
 Condensed Matter  Quantum Gases
 EPrint:
 8 pages, 13 Figures. Published version