论文标题
天空晶体中的量子拓扑相变
Quantum topological phase transitions in skyrmion crystals
论文作者
论文摘要
拓扑顺序在凝结物理学的许多方面都很重要，并且已扩展到骨系统。在这封信中，我们在两个不同的量子天空晶体中报告了磁条带的非平凡拓扑，出现在零外部磁场中。对于某些频段的非零Chern编号揭示了这一点。作为量子异常效应的骨式类似物，我们表明拓扑结晶物可以出现在Skyrmion晶体中，而不会明确破坏具有外部磁场的时间反转对称性。通过调整零温度下的易于轴各向异性的值，我们发现八个量子拓扑相变为不连续跳的某些Chern数字。我们将这些量子拓扑相变连接到镁带之间的差距闭合和重新打开。
Topological order is important in many aspects of condensed matter physics, and has been extended to bosonic systems. In this Letter we report on the nontrivial topology of the magnon bands in two distinct quantum skyrmion crystals appearing in zero external magnetic field. This is revealed by nonzero Chern numbers for some of the bands. As a bosonic analog of the quantum anomalous Hall effect, we show that topological magnons can appear in skyrmion crystals without explicitly breaking time-reversal symmetry with an external magnetic field. By tuning the value of the easy-axis anisotropy at zero temperature, we find eight quantum topological phase transitions signaled by discontinuous jumps in certain Chern numbers. We connect these quantum topological phase transitions to gaps closing and reopening between magnon bands.
