Identifying possible pairing states in Sr${}_2$RuO${}_4$ by tunneling spectroscopy

Abstract

We examine the tunneling spectroscopy of three-dimensional normal-metal/Sr${}_2$RuO${}_4$ junctions as an experimental means to identify pairing symmetry in Sr${}_2$RuO${}_4$. In particular, we consider three different possible pairing states in Sr${}_2$RuO${}_4$: spin-singlet chiral $d$-wave, spin-triplet helical $p$-wave, and spin-nematic $f$-wave ones, all of which are consistent with recent nuclear-magnetic-resonance experiments [A. Pustogow et al., Nature 574, 72 (2019)]. The Blonder-Tinkham-Klapwijk theory is employed to calculate the tunneling conductance, and the cylindrical two-dimensional Fermi surface of Sr${}_2$RuO${}_4$ is properly taken into account as an anisotropic effective mass and a cutoff in the momentum integration. It is pointed out that the chiral $d$-wave pairing state is inconsistent with previous tunneling conductance experiments along the $c$-axis. We also find that the remaining candidates, the spin-triplet helical $p$-wave pairing state and the spin-nematic $f$-wave ones, can be distinguished from each other by the in-plane tunneling spectroscopy along the $a$- and $b$-axes.

9 pages, 9 figures, 1 table, accepted for publication in Physical Review B

References in corpus (12)

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Cited by in corpus (10)

• Aspects of topological superconductivity in 2D systems: noncollinear magnetism, skyrmions, and higher-order topology
• Destruction of surface states of ($d_{zx}+i{d}_{yz}$)-wave superconductor by surface roughness: application to Sr${}_2$RuO${}_4$
• Surface density of states and tunneling spectroscopy of a spin-3/2 superconductor with Bogoliubov Fermi Surfaces
• Robustness of chiral surface current and subdominant $s$-wave Cooper pairs
• Surface State of Inter-orbital Pairing State in Sr${}_2$RuO${}_4$ Superconductor
• Vortex supercurrent inversion by frequency-symmetry conversion of Cooper pairs
• Supercurrent reversal in Zeeman-split Josephson junctions
• Fingerprints of possible even-parity superconducting states in Sr${}_2$RuO${}_4$ detected by planar tunneling spectroscopy
• Chiral Current Inversion Induced by Flat-Band Andreev Bound States
• Josephson effects in the spin-triplet superconductor/altermagnet/spin-triplet superconductor junctions: the detection of the intrinsic $\mathbf{d}$-vector