标题： 杂质带在典型莫特-安德森转变中的离域化映射 显示英文标题

标题： Mapping delocalization of impurity bands across archetypal Mott-Anderson transition

摘要： 按需调整固体中的电荷输运是凝聚态研究的总体目标，因为它对电子应用至关重要。 然而，通常缺少适当的调节旋钮，杂质和无序等外部因素会阻碍相干传导。 在这里，我们通过减少Fe含量，控制三元Fe$_{2-x}$V$_{1+x}$Al Heusler化合物伪隙内杂质态的电子带结构的建立。 我们的密度泛函理论计算结合比热和电阻率实验表明，最初，在低V浓度下，这些态是Anderson局域化的$0 < x < 0.1$。 随着x的增加，我们在典型的Mott-Anderson转变中监测迁移率边的形成，并通过热电测量映射导电态的增加带宽。 最终，在完全无序的V$_3$Al中，电荷载流子的非局域化导致电阻率正好处于Mott-Ioffe-Regel极限，在700 K以下完全温度无关，比康铜更稳定。 显示英文摘要

摘要： Tailoring charge transport in solids on demand is the overarching goal of condensed-matter research as it is crucial for electronic applications. Yet, often the proper tuning knob is missing and extrinsic factors such as impurities and disorder impede coherent conduction. Here we control the very buildup of an electronic band from impurity states within the pseudogap of ternary Fe$_{2-x}$V$_{1+x}$Al Heusler compounds via reducing the Fe content. Our density functional theory calculations combined with specific heat and electrical resistivity experiments reveal that, initially, these states are Andersonlocalized at low V concentrations $0 < x < 0.1$. As x increases, we monitor the formation of mobility edges upon the archetypal Mott-Anderson transition and map the increasing bandwidth of conducting states by thermoelectric measurements. Ultimately, delocalization of charge carriers in fully disordered V$_3$Al results in a resistivity exactly at the Mott-Ioffe-Regel limit that is perfectly temperature-independent up to 700 K - more constant than constantan.