Physical properties of weak-coupling quasiperiodic superconductors
Physical properties of weak-coupling quasiperiodic superconductors
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DOI：
10.1103/physrevb.102.115108
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发表时间：
2020-05
影响因子：
3.7
通讯作者：
Nayuta Takemori;R. Arita;S. Sakai
中科院分区：
文献类型：
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作者：
Nayuta Takemori;R. Arita;S. Sakai
为了了解准晶中的超导电性，我们对准周期超导体的物理性质进行了数值研究。我们把Penrose瓦片上吸引人的Hubbard模型作为一个简单的理论模型，计算了各种基本的超导性质，并发现在恒定态密度近似下偏离了Bardeen-Cooper-Schrieffer理论的普适值。特别是，我们发现超导转变处的比热跳跃比普适值小约10%-20%，这与Al-Mg-Zn准晶超导合金的实验结果是一致的。此外，我们计算了电流-电压特性，发现与周期系统中的快速增加相反，彭罗斯瓷砖上的电流随着电压的增加而逐渐增加。这些区别源于准周期系统的非平凡库珀配对特性。
We numerically study the physical properties of quasiperiodic superconductors with the aim of understanding superconductivity in quasicrystals. Considering the attractive Hubbard model on the Penrose tiling as a simple theoretical model, we calculate various basic superconducting properties and find deviations from the universal values of the Bardeen-Cooper-Schrieffer theory with a constant density-of-states approximation. In particular, we find that the jump of the specific heat at the superconducting transition is about 10%--20% smaller than that universal value, consistent with the experimental results obtained for the superconducting Al-Mg-Zn quasicrystalline alloy. Furthermore, we calculate current-voltage characteristics and find that the current gradually increases with the voltage on the Penrose tiling in contrast to a rapid increase in the periodic system. These distinctions originate from the nontrivial Cooper pairing characteristic of the quasiperiodic system.