Coherence peak in the spin susceptibility from nesting in spin-triplet superconductors; A probe for line nodes in Sr${}_2$RuO${}_4$

Abstract

We study the dynamical spin susceptibility $\chi (\mathbf{q},\omega )$ for spin-triplet superconductivity. We show that a large peak at $\omega =2\Delta$ appears in $\text{Im}{\chi }_{zz}(\mathbf{Q},\omega )$, where $z$ is the direction of the $\mathbf{d}$ vector for triplet pairing, if Fermi surface has a nested part with the nesting vector $\mathbf{Q}$ and the order parameter is $+\Delta$ and $-\Delta$ in this part of the Fermi surface. If there are line nodes in the nested part of the Fermi surface, a peak appears in either $\text{Im}{\chi }_{zz}(\mathbf{Q},\omega )$ or $\text{Im}{\chi }_{+-}(\mathbf{Q},\omega )$, or both, depending on the perpendicular component of the nesting vector. The comparison with inelastic neutron scattering experiments can determine the position of the line nodes in triplet superconductor Sr${}_2$RuO${}_4$.

7 pages, 9 figures

References in corpus (1)

• Inelastic neutron scattering study of magnetic excitations in Sr${}_2$RuO${}_4$

Cited by in corpus (5)

• Feedback of superconductivity on the magnetic excitation spectrum of UTe${}_2$
• Absence of a large superconductivity-induced gap in magnetic fluctuations of Sr2RuO4
• Effects of hydrostatic pressure on the magnetic susceptibility of ruthenium oxide Sr3Ru2O7: Evidence for pressure-enhanced antiferromagnetic instability
• Interband Coulomb Interaction and Horizontal Line Nodes in Triplet Superconductor Sr${}_2$RuO${}_4$
• Dipole Interaction in Triplet Superconductivity with Horizontal Line Nodes; Orientation of the Superconducting Order Parameter in Sr2RuO4