Baldomir Daniel, Faílde Daniel
Departamento de Física Aplicada, Instituto de Investigacións Tecnolóxicas. Universidade de Santiago de Compostela, E-15782, Campus Vida s/n, Santiago de Compostela, Spain.
Sci Rep. 2019 Apr 19;9(1):6324. doi: 10.1038/s41598-019-42744-3.
Topological Insulators are the best thermoelectric materials involving a sophisticated physics beyond their solid state and electronic structure. We show that exists a topological contribution to the thermoelectric effect that arises between topological and thermal quantum field theories applied at very low energies. This formalism provides us with a quantized topological mass proportional to the temperature T leading, through an electric potential V, to a Seebeck coefficient where we identify an anomalous contribution that can be associated to the creation of real electron-hole Schwinger's pairs close to the topological bands. Finally, we find a general expression for the dimensionless figure of merit of these topological materials, considering only the electronic contribution, getting a value of 2.73 that is applicable to the BiTe, for which it was reported a value of 2.4 after reducing its phononic contribution, using only the most basic topological numbers (0 or 1).
拓扑绝缘体是最好的热电材料,涉及超越其固态和电子结构的复杂物理。我们表明,在极低能量下应用的拓扑量子场论和热量子场论之间存在对热电效应的拓扑贡献。这种形式主义为我们提供了一个与温度T成正比的量子化拓扑质量,通过电势V导致塞贝克系数,在其中我们识别出一个异常贡献,该贡献可与拓扑能带附近真实电子 - 空穴施温格对的产生相关联。最后,仅考虑电子贡献,我们找到了这些拓扑材料无量纲品质因数的一般表达式,得到的值为2.73,该值适用于BiTe,在仅使用最基本的拓扑数(0或1)减少其声子贡献后,据报道其值为2.4。