Arh T, Gomilšek M, Prelovšek P, Pregelj M, Klanjšek M, Ozarowski A, Clark S J, Lancaster T, Sun W, Mi J-X, Zorko A
Jožef Stefan Institute, Jamova c. 39, SI-1000 Ljubljana, Slovenia.
Faculty of Mathematics and Physics, University of Ljubljana, Jadranska u. 19, SI-1000 Ljubljana, Slovenia.
Phys Rev Lett. 2020 Jul 10;125(2):027203. doi: 10.1103/PhysRevLett.125.027203.
The ground state of the simple Heisenberg nearest-neighbor quantum kagome antiferromagnetic model is a magnetically disordered spin liquid, yet various perturbations may lead to fundamentally different states. Here we disclose the origin of magnetic ordering in the structurally perfect kagome material YCu_{3}(OH){6}Cl{3}, which is free of the widespread impurity problem. Ab initio calculations and modeling of its magnetic susceptibility reveal that, similar to the archetypal case of herbertsmithite, the nearest-neighbor exchange is by far the dominant isotropic interaction. Dzyaloshinskii-Moriya (DM) anisotropy deduced from electron spin resonance, susceptibility, and specific-heat data is, however, significantly larger than in herbertsmithite. By enhancing spin correlations within kagome planes, this anisotropy is essential for magnetic ordering. Our study isolates the effect of DM anisotropy from other perturbations and unambiguously confirms the predicted phase diagram.
简单的海森堡最近邻量子 kagome 反铁磁模型的基态是一种磁无序的自旋液体，但各种微扰可能导致截然不同的状态。在此，我们揭示了结构完美的 kagome 材料 YCu₃(OH)₆Cl₃ 中磁有序的起源，该材料不存在普遍存在的杂质问题。对其磁化率的从头算计算和建模表明，与原型矿物赫伯史密斯石的情况类似，最近邻交换是迄今为止占主导地位的各向同性相互作用。然而，从电子自旋共振、磁化率和比热数据推导出的 Dzyaloshinskii-Moriya（DM）各向异性明显大于赫伯史密斯石中的情况。通过增强 kagome 平面内的自旋关联，这种各向异性对于磁有序至关重要。我们的研究将 DM 各向异性的影响与其他微扰隔离开来，并明确证实了预测的相图。
