Spin triplet superconductivity with line nodes in Sr2RuO4

TL;DR

This paper investigates possible odd-parity spin triplet superconducting states in Sr2RuO4, identifying candidates with line nodes consistent with experimental observations, and characterizes their properties.

Contribution

The study lists and examines plausible odd-parity triplet pairing states in Sr2RuO4, highlighting those with line nodes that match experimental data.

Findings

Identifies f-wave pairing states with line nodes in Sr2RuO4.

Characterizes states with vertical and horizontal line nodes.

Suggests time-reversal symmetry breaking in these states.

Abstract

Several possible odd-parity states are listed up group-theoretically and examined in light of recent experiments on Sr$_2$RuO$_4$. Those include some of the $f$-wave pairing states, ${\mib d}({\mib k})\propto{\hat{\mib z}} k_xk_y(k_x + {\rm i}k_y)$ and ${\hat{\mib z}} (k_x^2-k_y^2)(k_x + {\rm i}k_y)$ and other ${\hat{\mib z}} (k_x + {\rm i}k_y)\cos ck_z$ ($c$ is the $c$-axis lattice constant) as most plausible candidates. These are time-reversal symmetry broken states and have line nodes running either vertically (the former two) or horizontally (the latter), consistent with experiments. Characterizations of these states and other possibilities are given.