论文标题
在Cu $ _2 $ IRO $ _3 $中实现的近距离Kitaev量子旋转液体的旋转激发
Spin excitations of a proximate Kitaev quantum spin liquid realized in Cu$_2$IrO$_3$
论文作者
论文摘要
在蜂窝晶格的角落排列的磁矩被预测在粘结依赖性的ISING相互作用之间的影响下形成了新型物质，Kitaev量子旋转液体。 Some layered honeycomb iridates and related materials, such as Na$_{2}$IrO$_{3}$ and $α$-RuCl$_{3}$, are proximate to Kitaev quantum spin liquid, but bosonic spin-wave excitations associated with undesirable antiferromagnetic long-range order mask the inherent properties of Kitaev Hamiltonian.在这里，我们使用$^{63} $ cu核四极杆共振在ir $ $^{4+} $ sites中的几乎理想的蜂窝质量$ s = 1/2 $中，在Cu $ _ {2} $ iro $ $ $ _ {3} $中揭示了低能旋转激发。我们证明，与Na $ _ {2} $ IRO $ _ {3} $不同，IR自旋波动没有证据表明在零外部磁场中迈向磁性长距离顺序的临界速度降低。此外，低能旋转激发光谱由具有与Ising Ithostions相当的较大激发差距的模式主导，这是Kitaev量子型自旋液体的主要征兆。
Magnetic moments arranged at the corners of a honeycomb lattice are predicted to form a novel state of matter, Kitaev quantum spin liquid, under the influence of frustration effects between bond-dependent Ising interactions. Some layered honeycomb iridates and related materials, such as Na$_{2}$IrO$_{3}$ and $α$-RuCl$_{3}$, are proximate to Kitaev quantum spin liquid, but bosonic spin-wave excitations associated with undesirable antiferromagnetic long-range order mask the inherent properties of Kitaev Hamiltonian. Here, we use $^{63}$Cu nuclear quadrupole resonance to uncover the low energy spin excitations in the nearly ideal honeycomb lattice of effective spin $S = 1/2$ at the Ir$^{4+}$ sites in Cu$_{2}$IrO$_{3}$. We demonstrate that, unlike Na$_{2}$IrO$_{3}$, Ir spin fluctuations exhibit no evidence for critical slowing down toward magnetic long range order in zero external magnetic field. Moreover, the low energy spin excitation spectrum is dominated by a mode that has a large excitation gap comparable to the Ising interactions, a signature expected for Majorana fermions of Kitaev quantum spin liquid.
