论文标题
Berezinskii-Kosterlitz-沮丧的磁铁中的无尽阶段的证据
Evidence of the Berezinskii-Kosterlitz-Thouless Phase in a Frustrated Magnet
论文作者
论文摘要
Berezinskii-Kosterlitz-thouless（BKT）机制，建立在2D系统中拓扑缺陷的基础上，是超出对称性破坏的Landau-Ginzburg范式之外的相变的第一个例子。这种拓扑相过渡长期以来一直在寻求，但直接在磁性材料中未被发现。在这里，我们通过在平面内磁场下通过核磁共振结合了理想的2D挫折磁铁TMMGGAO $ _4 $的两个过渡，这些过渡将在理想的2D沮丧的磁铁tmmggao $ _4 $中固定，这不会干扰低能的电子状态并允许敏感地检测到BKT波动。此外，通过应用平面外磁场，我们发现BKT转变预期的磁敏感性的临界缩放行为。实验发现可以通过在载有BKT相的化合物的精确三角形晶格模型上应用的量子蒙特卡洛模拟来解释。这些结果为BKT阶段提供了一个具体的示例，并为将来研究磁性材料的BKT物理学提供了理想的平台。
The Berezinskii-Kosterlitz-Thouless (BKT) mechanism, building upon proliferation of topological defects in 2D systems, is the first example of phase transition beyond the Landau-Ginzburg paradigm of symmetry breaking. Such a topological phase transition has long been sought yet undiscovered directly in magnetic materials. Here, we pin down two transitions that bound a BKT phase in an ideal 2D frustrated magnet TmMgGaO$_4$, via nuclear magnetic resonance under in-plane magnetic fields, which do not disturb the low-energy electronic states and allow BKT fluctuations to be detected sensitively. Moreover, by applying out-of-plane fields, we find a critical scaling behaviour of the magnetic susceptibility expected for the BKT transition. The experimental findings can be explained by quantum Monte Carlo simulations applied on an accurate triangular-lattice Ising model of the compound which hosts a BKT phase. These results provide a concrete example for the BKT phase and offer an ideal platform for future investigations on the BKT physics in magnetic materials.
