A family of spin–orbit coupled honeycomb Mott insulators offers a playground to search for quantum spin liquids (QSLs) via bond-dependent interactions. In candidate materials, a symmetric off-diagonal Γ term, close cousin of Kitaev interaction, has emerged as another source of frustration that is essential for complete understanding of these systems. However, the ground state of honeycomb Γ model remains elusive, with a suggested zigzag magnetic order. Here we attempt to resolve the puzzle by perturbing the Γ region with a staggered Heisenberg interaction which favours the zigzag ordering. Despite such favour, we find a wide disordered region inclusive of the Γ limit in the phase diagram. Further, this phase exhibits a vanishing energy gap, a collapse of excitation spectrum, and a logarithmic entanglement entropy scaling on long cylinders, indicating a gapless QSL. Other quantities such as plaquette-plaquette correlation are also discussed.

一系列自旋轨道耦合蜂窝莫特绝缘体为通过键依赖相互作用寻找量子自旋液体 (QSL) 提供了一个平台。在候选材料中，对称的非对角 Γ 项（Kitaev 相互作用的近亲）已成为另一个令人沮丧的来源，这对于完全理解这些系统至关重要。然而，蜂窝 Γ 模型的基态仍然难以捉摸，具有建议的锯齿形磁序。在这里，我们试图通过用有利于锯齿形排序的交错海森堡相互作用扰动 Γ 区域来解决这个难题。尽管有这样的好处，我们还是发现了一个很宽的无序区域，包括相图中的 Γ 极限。此外，该相在长圆柱上表现出消失的能隙、激发光谱的坍塌和对数纠缠熵缩放，表示无间隙 QSL。还讨论了其他数量，例如斑块-斑块相关性。