Magnetism of multi-orbital edge states in Sr2RuO4

Abstract

Magnetic properties of edge states in the chiral p-wave superconductor Sr2RuO4 are investigated based on a multi-band model restricting to the two bands derived from the 4d-t2g d yz/dzx-orbitals. While generally low-energy gapless Andreev bound states appear at the edges which carry spontaneous charge current, they are not topologically protected. Including spin-orbit coupling of the two orbitals we find additionally edge spin currents which are present in the normal as well as the superconducting phase. They contribute to the anomalous and the spin Hall effect and generate in the superconducting phase a finite spin polarization at the surface. Repulsive onsite interaction strengthens the spin polarization through the coupling to a nesting driven incipient magnetic phase of the system. We speculate that the magnetizations of the spin polarization and the chiral edge currents could partially compensate each other, in view of recent experimental results. © Published under licence by IOP Publishing Ltd.