论文标题
在平面磁场下的$α$ -rucl $ _3 $中的ISing拓扑顺序
Testing Ising Topological Order in $α$-RuCl$_3$ Under In-Plane Magnetic Fields
论文作者
论文摘要
近年来，非亚伯kitaev自旋液相的物质实现 - 伊辛拓扑秩序（ITO）的一个例子（ITO）。 $ 4D $蜂窝状Mott绝缘子$α$ -rucl $ _3 $已成为领先的候选人，因为它进入了磁性诱发的磁性疾病状态，其中报告了半数量化的热霍尔电导率$κ__{xy} $。此外，最近的报告说，跨某个晶体学方向量化$κ_{xy} $的符号变化是有力的证据证明了两个具有相反Chern数字的ITO之间的拓扑相变。尽管这是一个令人着迷的结果，但独立验证仍然难以捉摸，并且可能会询问是否存在对相变敏感的热力学数量。在这里，我们建议在平面磁场下的磁型系数$ K $将达到这样的目的。我们报告了$ k $中的一个单数功能，该功能表明在$ \ hat {b} $ - 轴上进行了拓扑相变，其中ITO被$ C_2 $对称禁止。如果$α$ -rucl $ _3 $中的过渡确实是ITOS之间的直接过渡，则应可观察到$ k $中的此功能。
Material realization of the non-Abelian Kitaev spin liquid phase - an example of Ising topological order (ITO) - has been the subject of intense research in recent years. The $4d$ honeycomb Mott insulator $α$-RuCl$_3$ has emerged as a leading candidate, as it enters a field-induced magnetically disordered state where a half-integer quantized thermal Hall conductivity $κ_{xy}$ was reported. Further, a recent report of a sign change in the quantized $κ_{xy}$ across a certain crystallographic direction is strong evidence for a topological phase transition between two ITOs with opposite Chern numbers. Although this is a fascinating result, independent verification remains elusive, and one may ask if there is a thermodynamic quantity sensitive to the phase transition. Here we propose that the magnetotropic coefficient $k$ under in-plane magnetic fields would serve such a purpose. We report a singular feature in $k$ that indicates a topological phase transition across the $\hat{b}$-axis where ITO is prohibited by a $C_2$ symmetry. If the transition in $α$-RuCl$_3$ is indeed a direct transition between ITOs, then this feature in $k$ should be observable.
