论文标题
Heisenberg-Kitaev在磁场中的模型：$ 1/s $扩展
Heisenberg-Kitaev model in a magnetic field: $1/S$ expansion
论文作者
论文摘要
Kitaev的Spin- $ 1/2 $蜂窝状旋转液体模型的确切解决方案引发了对托管债券依赖的Kitaev Itsportation的强烈搜索，其中$ \ Mathrm {na} _ {2} _ {2}} \ Mathrm {iro}例子。随后，有人提出，在具有强旋转轨道耦合的材料中，可能会发生旋转$ 1 $和旋转$ 3/2 $的基塔夫相互作用。作为描述这些Kitaev材料的最小模型，我们以一致的$ 1/s $扩展来研究海森伯格 - 基塔夫·汉密尔顿人，其中$ s $是旋转尺寸。我们在沿两个不同方向[001]和[111]的外部磁场存在的情况下介绍了该模型的全面研究，为此报告了复杂的经典相图。在这两种情况下，我们在许多有序阶段中采用自旋波理论，以$ 1/s $的临近领先顺序计算相位边界，并显示量子校正实质上修改了经典相位图。从更广泛的角度来看，我们的工作提出了一条一致的途径，以研究破坏自旋旋转对称性的自旋模型中的领先量子校正。
The exact solution of Kitaev's spin-$1/2$ honeycomb spin-liquid model has sparked an intense search for Mott insulators hosting bond-dependent Kitaev interactions, of which $\mathrm{Na}_{2}\mathrm{IrO}_{3}$ and $α-\mathrm{RuCl}_{3}$ are prime examples. Subsequently, it has been proposed that also spin-$1$ and spin-$3/2$ analogs of Kitaev interactions may occur in materials with strong spin-orbit coupling. As a minimal model to describe these Kitaev materials, we study the Heisenberg-Kitaev Hamiltonian in a consistent $1/S$ expansion, with $S$ being the spin size. We present a comprehensive study of this model in the presence of an external magnetic field applied along two different directions, [001] and [111], for which an intricate classical phase diagram has been reported. In both settings, we employ spin-wave theory in a number of ordered phases to compute phase boundaries at the next-to-leading order in $1/S$ and show that quantum corrections substantially modify the classical phase diagram. More broadly, our work presents a consistent route to investigate the leading quantum corrections in spin models that break spin-rotational symmetry.
