论文标题
从\ emph {ab-initio}计算中的SNTE中的热拓扑相变
Thermal topological phase transition in SnTe from \emph{ab-initio} calculations
论文作者
论文摘要
拓扑绝缘子物理学的关键问题之一是在有限温度下是否可以在拓扑性非平凡的特性中存活，如果是的，它们是否仅在拓扑间隙截断的温度下消失。在这里，我们通过\ emph {ab-initio}方法研究了这个问题，该方法是通过\ emph {ab-initio}的方法来研究的，该方法是通过构建在\ emph {ab-initio}电子和声子条带结构顶部的有效耗散理论的补充的。在SNTE的情况下，原型晶体拓扑绝缘子，我们揭示了特征温度的存在，远低于关闭间隙的温度，这标志着拓扑状态连贯性的丧失。该过渡不存在于纯电子系统中，但是一旦我们与耗散的骨体浴起来，它就会出现。依赖性与保真度易感性的依赖性的特征可能与频带曲率的变化有关，但是拓扑相变的特征仅在忠诚度中才出现在忠诚度中，尽管非绝热耦合与软声子。我们的论点对山谷拓扑绝缘子有效，但原则上可以推广到具有任何破坏对称性玻色子的更广泛的拓扑绝缘子。
One of the key issues in the physics of topological insulators is whether the topologically non-trivial properties survive at finite temperatures and, if so, whether they disappear only at the temperature of topological gap closing. Here, we study this problem, using quantum fidelity as a measure, by means of \emph{ab-initio} methods supplemented by an effective dissipative theory built on the top of the \emph{ab-initio} electron and phonon band structures. In the case of SnTe, the prototypical crystal topological insulator, we reveal the presence of a characteristic temperature, much lower than the gap-closing one, that marks a loss of coherence of the topological state. The transition is not present in a purely electronic system but it appears once we invoke coupling with a dissipative bosonic bath. Features in the dependence with temperature of the fidelity susceptibility can be related to changes in the band curvature, but signatures of a topological phase transition appear in the fidelity only though the non-adiabatic coupling with soft phonons. Our argument is valid for valley topological insulators, but in principle can be generalized to the broader class of topological insulators which host any symmetry-breaking boson.
