论文标题
连续从手性旋转状态到具有Kitaev相互作用的锯齿形链中的共线磁顺序的连续过渡
Continuous phase transition from a chiral spin state to collinear magnetic order in a zigzag chain with Kitaev interactions
论文作者
论文摘要
量子自旋系统可以通过开发自发的磁化或旋转手性来打破时间逆转对称性。但是，在不同的对称性下，共线磁体和手性自旋状态是不变的，这意味着一相的顺序参数在另一个相中消失。我们展示了如何构建一维各向异性自旋模型，这些模型在此类状态之间表现出“ Landau-Forbidden”的连续相变。作为一个具体的例子，我们专注于具有债券依赖性交换和六旋相互作用的曲折链。使用精确的溶液，有效的场理论和数值模拟的组合，我们表明手性和磁相之间的过渡具有新兴的U（1）对称性。从手性阶段过渡的激发可以描绘成$ \ Mathbb Z_2 $通量配置中的移动缺陷，该配置绑定了费米子模式。我们简要讨论具有脱合量子关键的两个维度和类比的扩展。我们的结果表明，涉及手性旋转状态的非常规相变的新前景。
Quantum spin systems can break time reversal symmetry by developing spontaneous magnetization or spin chirality. However, collinear magnets and chiral spin states are invariant under different symmetries, implying that the order parameter of one phase vanishes in the other. We show how to construct one-dimensional anisotropic spin models that exhibit a "Landau-forbidden" continuous phase transition between such states. As a concrete example, we focus on a zigzag chain with bond-dependent exchange and six-spin interactions. Using a combination of exact solutions, effective field theories, and numerical simulations, we show that the transition between the chiral and magnetic phases has an emergent U(1) symmetry. The excitations governing the transition from the chiral phase can be pictured as mobile defects in a $\mathbb Z_2$ flux configuration which bind fermionic modes. We briefly discuss extensions to two dimensions and analogies with deconfined quantum criticality. Our results suggest new prospects for unconventional phase transitions involving chiral spin states.
