Properties of edge states in spin-triplet two-band superconductor

Abstract

Motivated by Sr2RuO4 the magnetic properties of edge states in a two-band spin-triplet superconductor with electron- and hole-like Fermi surfaces are investigated assuming chiral p-wave pairing symmetry. The two bands correspond to the alpha-beta-bands of Sr2RuO4 and are modeled within a tight-binding model including inter-orbital hybridization and spin-orbit coupling effects. Including superconductivity the quasiparticle spectrum is determined by means of a self-consistent Bogolyubov-de Gennes calculation. While a full quasiparticle excitation gap appears in the bulk, gapless states form at the edges which produce spontaneous spin and/or charge currents. The spin current is the result of the specific band structure while the charge current originates from the superconducting condensate. Together they induce a small spin polarization at the edge. Furthermore onsite Coulomb repulsion is included to show that the edge states are unstable against the formation of a Stoner-like spin polarization of the edge states. Through spin-orbit coupling the current- and the correlation-induced magnetism are coupled to the orientation of the chirality of the superconducting condensate. We speculate that this type of phenomenon could yield a compensation of the magnetic fields induced by currents and also explain the negative result in the recent experimental search for chiral edge currents.

9 pages, 13 figures, to appear in Physical Review B

References in corpus (5)

• High Resolution Polar Kerr Effect Measurements of Sr2RuO4: Evidence for Broken Time Reversal Symmetry in the Superconducting State
• Hidden quasi one-dimensional superconductivity in Sr${}_2$RuO${}_4$
• Giant Intrinsic Spin and Orbital Hall Effects in Sr2MO4 (M=Ru,Rh,Mo)
• Intrinsic anomalous Hall effect in ferromagnetic metals studied by the multi d-orbital tight-binding model
• Suppression of Spontaneous Supercurrents in a Chiral p-Wave Superconductor

Cited by in corpus (17)

• Vanishing edge currents in non-$p$-wave topological chiral superconductors
• Non-topological nature of the edge current in a chiral p-wave superconductor
• Suppression of spontaneous currents in Sr${}_2$RuO${}_4$ by surface disorder
• Spin Density Wave Fluctuations and p-wave Pairing in Sr2RuO4
• Spin-orbit coupling and spin-triplet pairing symmetry in $\mathrm{S}{\mathrm{r}}_2\mathrm{Ru}{\mathrm{O}}_4$
• Vortex Structures in Model p-Wave Superconducting Sr2RuO4 -- Single 2-Dimensional Band v.s. Quasi-1-Dimensional Band
• Surface magnetism in a chiral d-wave superconductor with hexagonal symmetry
• Possibility of mixed helical p-wave pairings in Sr${}_2$RuO${}_4$
• Quantum-geometry-induced anomalous Hall effect in nonunitary superconductors and application to Sr${}_2$RuO${}_4$
• Impurity induced magnetic ordering in Sr${}_2$RuO${}_4$
• Effect of the RuO6 octahedron rotation at the Sr2RuO4 surface on topological property
• Interband interference effects at the edge of a multiband chiral p-wave superconductor
• Strain-induced superconductivity in Sr2IrO4
• Thermal Hall conductivity in the spin-triplet superconductor with broken time-reversal symmetry
• Excitations at the border of a condensate
• Disorder-induced currents as signatures of chiral superconductivity
• Examining the possibility of chiral superconductivity in Sr${}_2$RuO${}_4$ and other compounds via applied supercurrent