Fumega Adolfo O, Pardo Victor, Cortijo A
Departamento de Física Aplicada, Universidade de Santiago de Compostela, Campus Sur s/n, 15782, Santiago de Compostela, Spain.
Instituto de Investigacións Tecnolóxicas, Universidade de Santiago de Compostela, Campus Sur s/n, 15782, Santiago de Compostela, Spain.
Sci Rep. 2021 May 19;11(1):10574. doi: 10.1038/s41598-021-90165-y.
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 BaSn[Formula: see text], 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 [Formula: see text] and [Formula: see text] orbitals and Sn [Formula: see text] 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.
压力的施加已被证明能在拓扑节线半金属中诱导出有趣的相变。在这项工作中，我们分析了单轴压力如何影响BaSn[化学式：见原文]的拓扑特性，BaSn[化学式：见原文]是一种在没有自旋轨道耦合时的狄拉克节线半金属。通过基于密度泛函理论的计算和一个模型紧束缚哈密顿量，我们发现对于高于4 GPa的压力会出现第二条节线。我们研究了两个相的拓扑特征，表明它们都具有非平凡特性。因此，提供了一个拓扑到拓扑相变的证据，其中拓扑节线的数量增加。发现Ba[化学式：见原文]和[化学式：见原文]轨道与Sn[化学式：见原文]轨道之间的轨道重叠增加以及晶体对称性的保持是这种相变出现的原因。此外，通过获得在施加磁场时每个相中出现的零能量模式之间的拓扑关系，我们为实验测试这种相变铺平了道路。
