Bahrami Faranak, Abramchuk Mykola, Lebedev Oleg, Tafti Fazel
Department of Physics, Boston College, Chestnut Hill, MA 02467, USA.
Laboratoire CRISMAT, ENSICAEN-CNRS UMR6508, 14050 Caen, France.
Molecules. 2022 Jan 27;27(3):871. doi: 10.3390/molecules27030871.
Nearly two decades ago, Alexei Kitaev proposed a model for spin-1/2 particles with bond-directional interactions on a two-dimensional honeycomb lattice which had the potential to host a quantum spin-liquid ground state. This work initiated numerous investigations to design and synthesize materials that would physically realize the Kitaev Hamiltonian. The first generation of such materials, such as Na2IrO3, α-Li2IrO3, and α-RuCl3, revealed the presence of non-Kitaev interactions such as the Heisenberg and off-diagonal exchange. Both physical pressure and chemical doping were used to tune the relative strength of the Kitaev and competing interactions; however, little progress was made towards achieving a purely Kitaev system. Here, we review the recent breakthrough in modifying Kitaev magnets via topochemical methods that has led to the second generation of Kitaev materials. We show how structural modifications due to the topotactic exchange reactions can alter the magnetic interactions in favor of a quantum spin-liquid phase.
近二十年前，阿列克谢·基塔耶夫提出了一个关于二维蜂窝晶格上具有键方向相互作用的自旋1/2粒子的模型，该模型有可能拥有量子自旋液体基态。这项工作引发了众多研究，旨在设计和合成能够物理实现基塔耶夫哈密顿量的材料。第一代这样的材料，如Na2IrO3、α-Li2IrO3和α-RuCl3，揭示了诸如海森堡和非对角交换等非基塔耶夫相互作用的存在。物理压力和化学掺杂都被用于调节基塔耶夫相互作用与竞争相互作用的相对强度；然而，在实现一个纯粹的基塔耶夫体系方面进展甚微。在此，我们回顾了通过拓扑化学方法修饰基塔耶夫磁体的近期突破，这导致了第二代基塔耶夫材料的出现。我们展示了由于拓扑交换反应引起的结构修饰如何能够改变磁相互作用，从而有利于量子自旋液体相。
