Evidence for a Field-Induced Quantum Spin Liquid in α-RuCl3
Evidence for a Field-Induced Quantum Spin Liquid in α-RuCl3
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DOI：
10.1103/physrevlett.119.037201
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发表时间：
2017-07-18
影响因子：
8.6
通讯作者：
Buechner, B.
中科院分区：
文献类型：
--
作者：
Baek, S-H.;Do, S-H.;Buechner, B.
我们报道了在蜂窝晶格α-RuCl3中进行的Cl-35核磁共振研究，这种材料被认为有可能实现Kitaev量子自旋液体(QSL)基态。我们的结果为α-RuCl3表现出磁场诱导的准分子发光提供了直接证据。对于大于10T的场，自旋间隙打开，而共振线保持尖锐，这证明自旋是量子无序的，局部起伏。自旋能隙随磁场的增加而线性增加，在15T时接近50K，且在磁场方向上接近各向同性。自旋能隙随场的反常快速增加及其各向同性的性质与传统的磁有序是不相容的，特别是排除了基态是全极化铁磁体的可能性。这种场诱导的带隙QSL相的存在确实已经在Kitaev模型中得到了预测。
We report a Cl-35 nuclear magnetic resonance study in the honeycomb lattice alpha-RuCl3, a material that has been suggested to potentially realize a Kitaev quantum spin liquid (QSL) ground state. Our results provide direct evidence that alpha-RuCl3 exhibits a magnetic-field-induced QSL. For fields larger than similar to 10 T, a spin gap opens up while resonance lines remain sharp, evidencing that spins are quantum disordered and locally fluctuating. The spin gap increases linearly with an increasing magnetic field, reaching similar to 50 K at 15 T, and is nearly isotropic with respect to the field direction. The unusual rapid increase of the spin gap with increasing field and its isotropic nature are incompatible with conventional magnetic ordering and, in particular, exclude that the ground state is a fully polarized ferromagnet. The presence of such a field-induced gapped QSL phase has indeed been predicted in the Kitaev model.