论文标题
由氧气空位雕刻和必不可少的稀释超导性的电子带
An electronic band sculpted by oxygen vacancies and indispensable for dilute superconductivity
论文作者
论文摘要
当费米温度远低于debye温度时，稀释的超导率在巨大的钛酸盐中生存。在这里，我们表明超导圆顶的发作是掺杂剂的依赖性的。当通过去除氧原子引入移动电子时，超导过渡的生存下降至$ 2 \ times 10^{17} $ cm $ $^{ - 3} $，但是当它们通过用ti替换NB时，超导率的阈值密度较高。我们对量子振荡的研究表明，这些掺杂途径制造的稀释金属之间的频带色散存在显着差异，而我们的频带计算表明，当通过氧气空位引入移动电子时，刚性频带近似不存在。我们将这些空缺雕刻的频带识别为超导不稳定的独特基因座。
Dilute superconductivity survives in bulk strontium titanate when the Fermi temperature falls well below the Debye temperature. Here, we show that the onset of the superconducting dome is dopant-dependent. When mobile electrons are introduced by removing oxygen atoms, the superconducting transition survives down to $2 \times 10^{17}$ cm$^{-3}$, but when they are brought by substituting Nb with Ti, the threshold density for superconductivity is an order of magnitude higher. Our study of quantum oscillations reveals a significant difference in the band dispersion between the dilute metals made by these doping routes and our band calculations demonstrate that the rigid band approximation does not hold when mobile electrons are introduced by oxygen vacancies. We identify the band sculpted by theses vacancies as the exclusive locus of superconducting instability in the ultra-dilute limit.
