论文标题
抗铁磁拓扑绝缘子中压力诱导的拓扑和结构相变
Pressure-induced Topological and Structural Phase Transitions in an Antiferromagnetic Topological Insulator
论文作者
论文摘要
最近，在理论上预测了（MNBI2TE4）M（BI2TE3）N的天然范德华异质结构（BI2TE3）N，并通过实验证明可以托有可调的磁性和拓扑上的非平凡表面状态。在这项工作中，我们系统地研究了MNBI2TE4和MNBI4TE7对外部压力的结构和电子响应。除了抑制抗磁磁序外，还发现MNBI2TE4在压缩后会发生金属 - 气门导管金属过渡。 MNBI4TE7的电阻率在高压下发生了巨大变化，并且观察到\ r {ho}（t）的非单调演化。事实证明，在高压方案中观察到的结构相变之前，非平凡的拓扑已被证明存在。我们发现散装状态和表面状态对压力的反应不同，这与电阻率的非单调变化一致。有趣的是，在MNBI2TE4中观察到了压力诱导的无定形状态，而MNBI4TE7在MNBI4TE7中揭示了两个高压相变。我们合并的理论和实验研究将MNBI2TE4和MNBI4TE7建立为高度可调的磁性绝缘体，其中相变和新的基态在压缩后出现。
Recently, natural van der Waals heterostructures of (MnBi2Te4)m(Bi2Te3)n have been theoretically predicted and experimentally shown to host tunable magnetic properties and topologically nontrivial surface states. In this work, we systematically investigate both the structural and electronic responses of MnBi2Te4 and MnBi4Te7 to external pressure. In addition to the suppression of antiferromagnetic order, MnBi2Te4 is found to undergo a metal-semiconductor-metal transition upon compression. The resistivity of MnBi4Te7 changes dramatically under high pressure and a non-monotonic evolution of \r{ho}(T) is observed. The nontrivial topology is proved to persists before the structural phase transition observed in the high-pressure regime. We find that the bulk and surface states respond differently to pressure, which is consistent with the non-monotonic change of the resistivity. Interestingly, a pressure-induced amorphous state is observed in MnBi2Te4, while two high pressure phase transitions are revealed in MnBi4Te7. Our combined theoretical and experimental research establishes MnBi2Te4 and MnBi4Te7 as highly tunable magnetic topological insulators, in which phase transitions and new ground states emerge upon compression.
