论文标题
蜂窝状晶格上的各向异性相互作用的海森堡 - $γ$模型的地面相图
Ground-state phase diagram of anisotropically interacting Heisenberg-$Γ$ models on a honeycomb lattice
论文作者
论文摘要
在本文中，我们调查了$ s = 1/2 $ heisenberg- $γ$模型的地面相图，该模型通过二聚体系列膨胀和精确的对角度化。我们关注相互作用各向异性的影响；通过调整耦合常数，系统在孤立的二聚体和自旋链模型之间发生变化。我们发现，在自旋链极限下，有三种状态：tomonaga-luttinger液体和两个磁性长期订购的状态。这三个状态通过无穷小的互链相互作用成为二维远程有序状态，除了海森贝格相互作用弱于非对抗对称（$γ$）相互作用的情况。从孤立的二聚体极限开始，三重二聚体相位在各个相图的大部分位置中生存到各向同性相互作用的系统，在该相位图中，海森堡和$γ$相互作用分别是铁磁和抗铁磁性。否则，在相互作用成为各向同性之前，相位向磁相变为磁相。这表明$γ$模型中提出的量子自旋液体[A。 Catuneanu等人，NPJ量子母校。 3，23（2018）]不稳定相互作用的各向异性。
In this paper, we investigate the ground-state phase diagram of the $S=1/2$ Heisenberg-$Γ$ model on a honeycomb lattice by dimer series expansion and exact diagonalization. We focus on the effects of the anisotropy of the interactions; by tuning the coupling constants, the system changes between the isolated dimer and the spin-chain models. We find that, in the spin-chain limit, there are three kinds of states: a Tomonaga-Luttinger liquid and two magnetically long-range-ordered states. All three states become two-dimensional long-range ordered states by the infinitesimal interchain interaction except for the case where the Heisenberg interaction is much weaker than the off-diagonal symmetric ($Γ$) interaction. Starting from the isolated dimer limit, a triplet dimer phase survives up to the isotropically interacting system in a large part of the phase diagram where the Heisenberg and $Γ$ interactions are ferromagnetic and antiferromagnetic, respectively. Otherwise, a phase transition to a magnetically ordered phase occurs before the interaction becomes isotropic. This indicates that the quantum spin liquid proposed in the $Γ$ model [A. Catuneanu et al., npj Quantum Mater. 3, 23 (2018)] is unstable against the anisotropy of the interactions.
