arXiv:1907.04709 · Physical review. B./Physical review. B
Quantum phase diagram of a frustrated spin- 12 system on a trellis ladder
Debasmita Maiti, Manoranjan Kumar
Abstract
We study an isotropic Heisenberg spin-$\frac{1}{2}$ model on a trellis ladder which is composed of two ${J}_{1}\ensuremath{-}{J}_{2}$ zigzag ladders interacting through antiferromagnetic rung coupling ${J}_{3}$. ${J}_{1}$ and ${J}_{2}$ are ferromagnetic zigzag spin interaction between two legs and antiferromagnetic interaction along each leg of a zigzag ladder. A quantum phase diagram of this model is constructed using the density matrix renormalization group method and linearized spin-wave analysis. In the small ${J}_{2}$ limit, a short-range striped collinear phase is found in the presence of ${J}_{3}$, whereas, in the large ${J}_{2}/{J}_{3}$ limit, a noncollinear quasi-long-range phase is found. The system shows a short-range noncollinear state in the large ${J}_{3}$ limit. The short-range-order phase is the dominant feature of this phase diagram. We also show that the results obtained by DMRG and linearized spin-wave analysis show a similar phase boundary between the collinear striped and noncollinear short-range phases, and the collinear phase region shrinks with increasing ${J}_{3}$. We apply this model to understand the magnetic properties of ${\mathrm{CaV}}_{2}{\mathrm{O}}_{5}$ and also fit the experimental data of susceptibility and magnetization. We note that ${J}_{3}$ is a dominant interaction in this material, whereas ${J}_{1}$ and ${J}_{2}$ are approximately half of ${J}_{3}$. The variation of magnetic specific heat capacity as a function of temperature for various external magnetic fields is also predicted.