Electronic theory for superconductivity in Sr${}_2$RuO${}_4$: triplet pairing due to spin-fluctuation exchange

Abstract

Using a two-dimensional Hubbard Hamiltonian for the three electronic bands crossing the Fermi level in Sr${}_2$RuO${}_4$ we calculate the band structure and spin susceptibility $\chi (\mathbf{q},\omega )$ in quantitative agreement with nuclear magnetic resonance (NMR) and inelastic neutron scattering (INS) experiments. The susceptibility has two peaks at {\bf Q}${}_i=(2\pi /3,2\pi /3)$ due to the nesting Fermi surface properties and at {\bf q}${}_i=(0.6\pi ,0)$ due to the tendency towards ferromagnetism. Applying spin-fluctuation exchange theory as in layered cuprates we determine from $\chi (\mathbf{q},\omega )$, electronic dispersions, and Fermi surface topology that superconductivity in Sr${}_2$RuO${}_4$ consists of triplet pairing. Combining the Fermi surface topology and the results for $\chi (\mathbf{q},\omega )$ we can exclude $s-$ and $d-$wave symmetry for the superconducting order parameter. Furthermore, within our analysis and approximations we find that $f$-wave symmetry is slightly favored over p-wave symmetry due to the nesting properties of the Fermi surface.

5 pages, 5 figures, misprints corrected

References in corpus (5)

• Superconducting Gap Structure of Spin-Triplet Superconductor Sr_2RuO_4 Studied by Thermal Conductivity
• Interband proximity effect and nodes of superconducting gap in Sr2RuO4
• Ultrasound Attenuation in Sr${}_2$RuO${}_4$: an Angle-Resolved Study of the Superconducting Gap Function
• Anisotropy of magnetothermal conductivity in Sr2RuO4
• A crib-shaped triplet pairing gap function for an orthogonal pair of quasi-one dimensional Fermi surfaces in Sr${}_2$RuO${}_4$

Cited by in corpus (15)

• Gap Structure of the Spin-Triplet Superconductor Sr2RuO4 Determined from the Field-Orientation Dependence of Specific Heat
• Determination of the Superconducting Gap Structure in All Bands of the Spin-Triplet Superconductor Sr2RuO4
• Pairing symmetry of the one-band Hubbard model in the paramagnetic weak-coupling limit: a numerical RPA study
• Magnetic response of Sr${}_2$RuO${}_4$: quasi-local spin fluctuations due to Hund's coupling
• Inelastic neutron scattering study of the magnetic fluctuations in Sr${}_2$RuO${}_4$
• Quantum Monte Carlo study of the pairing symmetry competition in the Hubbard model
• Theory of the Evolution of Superconductivity in Sr${}_2$RuO${}_4$ under Anisotropic Strain
• Pauli-paramagnetic effects on mixed state properties in a strongly anisotropic superconductor ---Application to Sr_2_RuO_4_---
• Spin triplet superconductivity driven by finite momentum spin fluctuations
• Superconducting phase diagram of itinerant antiferromagnets
• Low temperature electronic properties of Sr_2RuO_4 II: Superconductivity
• Excess current in superconducting Sr${}_2$RuO${}_4$
• Two-dimensional incommensurate magnetic fluctuations in Sr${}_2$(Ru${}_{0.99}$Ti${}_{0.01}$)O${}_4$
• Low temperature electronic properties of Sr_2RuO_4 I: Microscopic model and normal state properties
• Competing spin-fluctuations in Sr${}_2$RuO${}_4$ and their tuning through epitaxial strain