Superconducting Instability From Spin Fluctuations in Sr2RuO4

TKM Institutsseminar


Astrid Rømer


06/05/2021 14:00




University Kopenhagen


Dr. Roland Willa


During the last couple of years, research on the enigmatic and canonical unconventional superconductor Sr2RuO4 has undergone a renaissance. In particular, new nuclear magnetic resonance and ultrasound experiments [1,2,3] place considerable constraints on the superconducting order parameter. At the same time, Sr2RuO4 is in many respects simple enough that we should be able to understand why and how electrons pair. Superconductivity condenses around 1K from a well-characterized Fermi liquid, and samples are extremely clean.
I will discuss which superconducting order parameters are favorable from the perspective of spin-fluctuation mediated pairing, taking into account the multi-orbital nature of the system [4,5]. Effects of spin-orbit coupling and interactions are addressed and the proposed superconducting solution is compared to the available experimental data.

[1] A. Pustogow et al., Nature 574, 72–75 (2019).
[2] Sayak Ghosh et al., Nat. Phys. (2020).
[3] S. Benhabib et al., Nat. Phys. (2020).
[4] A. T. Rømer et al. Phys. Rev. Lett. 123, 247001 (2019).
[5] A. T. Rømer, P. J. Hirschfeld, B. M. Andersen preprint arXiv:2101.06972 (2021).