Pair-breaking vs. pair-conserving scattering in superconductors: implications for ARPES and superfluid stiffness
27.06.2017
| Date | 27.06.2017 |
|---|---|
| Time | 11:00 |
| Place |
|
| Speaker | Richard Hlubina |
| Area of expertise | Physics |
| Host | Dep. Physik |
| Contact | Sigrist |
| Abstract | The recent experimental study of how the superfluid stiffness in the cuprates disappears with overdoping [1] calls for a more complete understanding of the effect of disorder in unconventional d-wave superconductors. Of crucial importance is to distinguish pair-breaking (large-angle) from pair-conserving (small-angle) scattering processes, since they affect electromagnetic properties in very different ways [2]. I will argue that there exists a simple generic formula for the electron Green's function which takes into account both types of processes, and which moreover has the correct analytic properties, satisfies the known sum rules, and its spectral function is positive-definite [3,4]. I will demonstrate that the recent high-resolution ARPES data [5] can be fitted well by this formula, and that from the fit one can directly determine the relative weight of the pair-breaking and pair-conserving scattering processes. We find that in the cuprates the small-angle scattering processes are dominant [3], in agreement with arguments based on comparison between ARPES and transport. I will also present the implications of our theory for the doping- and temperature-dependence of the superfluid stiffness in overdoped cuprates. [1] I. Bozovic et al, Nature 536, 309 (2016). [2] F. Herman and R. Hlubina, preprint arXiv:1705.04674. [3] F. Herman and R. Hlubina, Phys. Rev. B 95, 094514 (2017). [4] F. Herman and R. Hlubina, Phys. Rev. B 94, 144508 (2016). [5] T. Kondo et al., Nat. Commun. 6, 7699 (2015). |