Pair-pair interactions in high-Tc superconductivity: Evidence from tunneling experiments
Sorbonne Universities, Paris
The conventional BCS theory fails to account for the physical properties of a large variety of high-Tc superconductors, the cuprate family and the recently discovered iron-based superconductors. In particular, these materials reveal a `peak-dip-hump' structure in the quasiparticle DOS at low temperature and often a pseudogap at the critical temperature.
In my talk, the origin of these features are explained in the framework of a new pair-pair interaction model :
- The non-superconducting state consists of incoherent pairs, a `Cooper-pair glass' which, due to the pair-pair interaction, condense below Tc to the coherent superconducting state.
- The peak-dip-hump structure is then due to the strong coupling between quasiparticles and excited pairs, which we call `super-quasiparticles'.
The talk will focus on a wide variety of tunneling experiments, with varied temperature, magnetic field and doping, to test the validity of the model.
 W. Sacks, A. Mauger, Y. Noat, Superconduct. Sci. Technol. 28 105014, (2015)