标题： 热电证据显示FeGe在电荷密度波转变中的电子结构变化 显示英文标题

标题： Thermoelectric evidence of the electronic structure changes from the charge-density-wave transition in FeGe

摘要： 由于其电子结构中天然包含线性色散、平带和范霍夫奇点，kagome金属为研究新的关联量子现象提供了材料平台。 其中一种量子现象是电荷密度波（CDW），或由于关联电子在材料中的运动导致的晶格结构畸变。 CDW降低了化合物的能量，形成一个能隙，促进了类似于超导性、非线性输运或其他量子关联现象的行为。 kagome金属FeGe已被证明在约100 K时出现CDW转变，其出现受到样品退火条件的强烈影响。 然而，文献中一个显著的空白是缺乏与这种CDW转变相关的电子结构变化的明确热电输运证据。 在这里，我们通过热电测量提供了关于退火无序导致电子行为改变的证据，这些测量对象是表现出CDW转变的FeGe晶体以及没有CDW的晶体。 在充分退火条件下的观察到的能斯特效应和塞贝克效应表明，由于诱导的无序，电气输运特性发生了改变，包括载流子符号的变化以及由于CDW引起的能斯特效应增强。 我们的结果提供了多个相变的证据，这证实了CDW对FeGe热性能的影响，并展示了足够无序下CDW的抑制。 显示英文摘要

摘要： Kagome metals provide a material platform for probing new correlated quantum phenomena due to the naturally incorporated linear dispersions, flat bands, and Van Hove singularities in their electronic structures. Among these quantum phenomena is the charge density wave (CDW), or the distortion of the lattice structure due to the motion of correlated electrons through the material. CDWs lower the energy of the compound, creating an energy gap that facilitates behaviors akin to superconductivity, nonlinear transport, or other quantum correlated phenomena. The kagome metal FeGe has been shown to host a CDW transition at approximately 100 K, and its occurrence is strongly influenced by the sample annealing conditions. However, a notable gap in the literature is the lack of clear thermoelectric transport evidence for electronic structure changes associated with this CDW transition. Here we present evidence of electron behavior modification due to annealing disorder via thermoelectric measurements on FeGe crystals presenting a CDW transition and those without a CDW. The observed Nernst effect and Seebeck effect under sufficient annealing demonstrate modified electrical transport properties resulting from induced disorder, including a change in carrier sign and an enhancement of the Nernst effect due to the CDW. Our results provide evidence of multiple phase transitions, which confirms the influence of CDW on the thermal properties of FeGe and demonstrates the suppression of CDW with sufficient disordering.