Gaps of cuprate high temperature superconductors

作者：Huefner S^*; Mueller F

来源：Physica C-Superconductivity and Its Applications, 2013, 485: 83-88.

DOI：10.1016/j.physc.2012.10.009

• Tunnelling
• High temperature superconductivity
• Superconducting gap
• Pseudogap

While in conventional superconductors Andreev Reflection (AR) and Giaever Tunnelling (GT) measure the same gap, this is not the case for the Cuprate High Temperature Superconductors (CHTSCs). This can be rationalized by interpreting AR in the CHTSC as an experiment, where a pseudogap pair impinges on the normal metal superconductor interface and is transformed into a superconducting boson. This process is governed by the superconducting gap, which is smaller than the pseudogap. B-2g Raman scattering and neutron scattering can be regarded as inverse AR experiments and thus they also measure the superconducting gap. The difference in AR and GT data is therefore an indication for the pseudogap state being a precursor state to the superconducting state in the CHTSC. However, another interpretations of the pseudogap is also discussed in the literature, namely one where the pseudogap represents competing order. As a matter of fact, the literature on the pseudogap has been dominated by the question whether this gap presents preformed pairs or competing order. Recent data can be possibly interpreted that indeed both of these pseudogaps are present in the CHTSC.

• 出版日期2013-2