Horizontal Line Nodes in Sr2RuO4 Proved by Spin Resonance
- Resource Type
- Working Paper
- Authors
- Iida, K.; Kofu, M.; Suzuki, K.; Murai, N.; Ohira-Kawamura, S.; Kajimoto, R.; Inamura, Y.; Ishikado, M.; Hasegawa, S.; Masuda, T.; Yoshida, Y.; Kakurai, K.; Machida, K.; Lee, S. -H.
- Source
- J. Phys. Soc. Jpn. 89, 053702 (2020)
- Subject
- Condensed Matter - Superconductivity
- Language
We investigated the low-energy incommensurate (IC) magnetic fluctuations in Sr$_2$RuO$_4$ by the high-resolution inelastic neutron scattering measurements and random phase approximation (RPA) calculations. We observed a spin resonance with energy of $\hbar\omega_\text{res}=0.56$~meV centered at a characteristic wavevector $\mathbf{Q}_\text{res}=(0.3, 0.3, 0.5)$. The resonance energy corresponds well to the superconducting gap $2\Delta=0.56$~meV estimated by the tunneling spectroscopy. The spin resonance shows the $L$ modulation with a maximum at around $L = 0.5$. The $L$ modulated intensity of the spin resonance and our RPA calculations indicate that the superconducting gaps regarding the quasi-one-dimensional $\alpha$ and $\beta$ sheets at the Fermi surfaces have the horizontal line nodes. These results may set a strong constraint on the pairing symmetry of Sr$_2$RuO$_4$. We also discuss the implications on possible superconducting order parameters.
Comment: arXiv admin note: substantial text overlap with arXiv:1904.01234