论文标题
节点半含量的伪组形成
Pseudogap Formation in the Nodal-Line Semimetal NaAlGe
论文作者
论文摘要
Naalsi和Naalge是等值和等电子半学，拓扑结节线接近费米水平。尽管具有几乎相同的电子结构，但Naalsi在TC = 6.8 K以下表现出超导性，而Naalge则没有。我们通过测量使用单晶的电阻率，霍尔效应，磁敏感性和热容量来研究NAALGE。据揭示，Naalge不是一个简单的半学，而是具有不寻常的基态，其较小的伪模近约100 K接近费米水平。我们认为，naalge中伪群的形成是由于意外的费米表面不稳定性，例如激子的不稳定性，而不是导致Naalsi中超导间隙形成的电子 - phonon不稳定性。
NaAlSi and NaAlGe are isostructural and isoelectronic semimetals with topological nodal lines close to the Fermi level. Despite having virtually identical electronic structures, NaAlSi exhibits superconductivity below Tc = 6.8 K, whereas NaAlGe does not. We investigate NaAlGe by measuring its electrical resistivity, Hall effect, magnetic susceptibility, and heat capacity using single crystals. It is revealed that NaAlGe is not a simple semimetal but rather has an unusual ground state with a small pseudogap of approximately 100 K close to the Fermi level. We argue that the formation of the pseudogap in NaAlGe is due to an unexpected Fermi surface instability, such as an excitonic instability, as opposed to the electron-phonon instability that leads to the formation of the superconducting gap in NaAlSi.
