论文标题
超级晶格样MNBI2TE4/（BI2TE3）N拓扑绝缘子中的压力调节的内部交换
Pressure-tuned intralayer exchange in superlattice-like MnBi2Te4/(Bi2Te3)n topological insulators
论文作者
论文摘要
MNBI2TE4（BI2TE3）n的磁结构可以通过通过BI2TE3间隔层N进行调整层偶联来操纵，而层间内的铁磁（FM）交换耦合被认为太强大而无法控制。通过施加高达3.5 GPA的静水压力，我们发现了n = 1和2的磁性能的相反响应。MNBI4TE7保持在A型抗铁磁性（AFM）相，而Néel温度降低，并且饱和场的增加。相比之下，MNBI6TE10经历了从A型AFM到准二维FM状态的相变，在压力下具有抑制饱和场。第一原理计算揭示了晶格压缩中内部交换耦合在确定这些磁性特性中的重要作用。由于平面晶格压缩，在20％掺杂的MNBI6TE10中还观察到了这种磁相变。
The magnetic structures of MnBi2Te4(Bi2Te3)n can be manipulated by tuning the interlayer coupling via the number of Bi2Te3 spacer layers n, while the intralayer ferromagnetic (FM) exchange coupling is considered too robust to control. By applying hydrostatic pressure up to 3.5 GPa, we discover opposite responses of magnetic properties for n = 1 and 2. MnBi4Te7 stays at A-type antiferromagnetic (AFM) phase with a decreasing Néel temperature and an increasing saturation field. In sharp contrast, MnBi6Te10 experiences a phase transition from A-type AFM to a quasi-two-dimensional FM state with a suppressed saturation field under pressure. First-principles calculations reveal the essential role of intralayer exchange coupling from lattice compression in determining these magnetic properties. Such magnetic phase transition is also observed in 20% Sb-doped MnBi6Te10 due to the in-plane lattice compression.
