Abstract

We discuss the pairing symmetry of a cobaltate superconductor ${\mathrm{Na}}_{x}{\mathrm{CoO}}_{2}\ifmmode\cdot\else\textperiodcentered\fi{}y\phantom{\rule{0.3em}{0ex}}{\mathrm{H}}_{2}\mathrm{O}$ by adopting an effective single-band model that takes into account the ${e}_{g}^{\ensuremath{'}}$ hole pockets, as discussed in our previous paper [Phys. Rev. Lett. 93, 077001 (2004)]. Here we consider the off-site repulsions in addition to the on-site repulsion considered in our previous study. We show that the spin-triplet $f$-wave pairing proposed in our previous study is robust to some extent even in the presence of off-site repulsions. However, $f$-wave pairing gives way to singlet pairings for sufficiently large values of off-site repulsions. Among the singlet pairings, $i$-wave and extended $s$-wave pairings are good candidates which do not break time reversal symmetry below ${T}_{c}$ in agreement with the experiments.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.