Faílde Daniel, Baldomir Daniel
Departamento de Física Aplicada, Instituto de Investigacións Tecnolóxicas, Universidade de Santiago de Compostela, Campus Vida s/n, 15782, Santiago de Compostela, Spain.
Sci Rep. 2021 Jul 12;11(1):14335. doi: 10.1038/s41598-021-93667-x.
Topological edge states are predicted to be responsible for the high efficient thermoelectric response of topological insulators, currently the best thermoelectric materials. However, to explain their figure of merit the coexistence of topological electrons, entropy and phonons can not be considered independently. In a background that puts together electrodynamics and topology, through an expression for the topological intrinsic field, we treat relativistic phonons within the topological surface showing their ability to modulate the Berry curvature of the bands and then playing a fundamental role in the thermoelectric effect. Finally, we show how the topological insulators under such relativistic thermal excitations keep time reversal symmetry allowing the observation of high figures of merit at high temperatures. The emergence of this new intrinsic topological field and other constraints are suitable to have experimental consequences opening new possibilities of improving the efficiency of this topological effect for their based technology.
拓扑边缘态被认为是拓扑绝缘体高效热电响应的原因，拓扑绝缘体是目前最好的热电材料。然而，为了解释它们的品质因数，不能独立考虑拓扑电子、熵和声子的共存。在一个将电动力学和拓扑学结合在一起的背景下，通过拓扑本征场的表达式，我们在拓扑表面处理相对论声子，展示了它们调节能带贝里曲率的能力，进而在热电效应中发挥重要作用。最后，我们展示了在这种相对论热激发下的拓扑绝缘体如何保持时间反演对称性，从而在高温下能够观察到高的品质因数。这种新的本征拓扑场的出现和其他约束条件适合产生实验结果，为基于这种拓扑效应的技术提高效率开辟新的可能性。
