论文标题
通过单轴压力增加半学中拓扑结节线的数量
Increasing the number of topological nodal lines in semimetals via uniaxial pressure
论文作者
论文摘要
已证明压力的应用可以诱导拓扑结节线半学的有趣相变。在这项工作中，我们分析了单轴压力如何影响BASN2的拓扑特征，Basn2是在没有自旋轨道耦合的情况下Dirac节点线的半学。使用基于密度函数理论和模型紧密结合的哈密顿量的计算，我们发现第二个节点线的出现，用于高于4 GPA的压力。我们检查了两个阶段的拓扑特征，表明它们两个都存在非平凡的特征。因此，提供了拓扑相变的证据，其中拓扑结节线的数量增加。 BA DXZ和DYZ轨道和SN PZ轨道之间的轨道重叠增加，并且发现晶体对称性的保存是该过渡的出现的原因。此外，我们通过在应用磁场时在每个阶段出现的零能量模式之间获得拓扑关系来为实验测试这种过渡铺平道路。
The application of pressure has been demonstrated to induce intriguing phase transitions in topological nodal-line semimetals. In this work we analyze how uniaxial pressure affects the topological character of BaSn2 , a Dirac nodal-line semimetal in the absence of spin-orbit coupling. Using calculations based on the density functional theory and a model tight-binding Hamiltonian, we find the emergence of a second nodal line for pressures higher than 4 GPa. We examine the topological features of both phases demonstrating that a nontrivial character is present in both of them. Thus, providing evidence of a topological-to-topological phase transition in which the number of topological nodal lines increases. The orbital overlap increase between Ba dxz and dyz orbitals and Sn pz orbitals and the preservation of crystal symmetries are found to be responsible for the advent of this transition. Furthermore, we pave the way to experimentally test this kind of transition by obtaining a topological relation between the zero-energy modes that arise in each phase when a magnetic field is applied.
