Magnetic ground state in the Kitaev honeycomb-lattice antiferromagnet cancicate Yb2Ba9Si6O24

Quantum spin liquid (QSL) is a disordered state where quantum fluctuations suppress magnetic ordering. Strong entanglement between magnetic moments enables topological excitations, essential for robust quantum computing. Kitaev model of S = 1/2 spins on a honeycomb lattice coupled by bond-direction dependent interactions is a rare case of an exactly solvable model with QSL ground state, and thus highly appealing. Yet, candidate materials are scarce and hindered by additional interactions and structural imperfections. We propose to study a magnetic ground state of a new honeycomb lattice compound Yb2Si6Ba9O24 involving Yb3+ magnetic ions that have highly localized 4f orbitals and promise less distortion than other systems. The understanding of the magnetic ordering will alow for determination of the spin Hamilotinan and hereby reveal how close is this system to a perfect Kitave model.

量子自旋液体（Quantum spin liquid, QSL）是量子涨落抑制磁有序的无序态。磁矩间的强纠缠可产生拓扑激发，这对稳健的量子计算至关重要。Kitaev模型描述蜂窝晶格上S=1/2自旋通过键方向依赖的相互作用耦合的系统，是少数具有QSL基态且可精确求解的模型之一，因此极具吸引力。然而，候选材料稀缺，且受额外相互作用和结构缺陷的阻碍。我们提出研究新型蜂窝晶格化合物Yb₂Si₆Ba₉O₂₄的磁基态，该化合物包含Yb³⁺磁离子，其4f轨道高度局域化，有望比其他系统具有更少的畸变。对磁有序的理解将有助于确定自旋哈密顿量（spin Hamiltonian），并由此揭示该系统与理想Kitaev模型的接近程度。