arXiv:cond-mat/0604495 · Physical Review B
Magnetic phase diagram of a frustrated ferrimagnetic ladder: Relation to the one-dimensional boson Hubbard model
Nedko B. Ivanov, Johannes Richter
Abstract
We study the magnetic phase diagram of two coupled mixed-spin $(1,\frac{1}{2})$ Heisenberg chains as a function of the frustration parameter related to diagonal exchange couplings. The analysis is performed by using spin-wave series and exact numerical diagonalization techniques. The obtained phase diagram---containing the Luttinger liquid phase, the plateau phase with a magnetization per rung $M=1∕2$, and the fully polarized phase---is closely related to the generic $(J∕U,\ensuremath{\mu}∕U)$ phase diagram of the one-dimensional boson Hubbard model.