Antiferromagnetism in RuO₂ as d -wave Pomeranchuk instability

Abstract

We present a computational study of antiferromagnetic transition in RuO2. The rutile structure with the magnetic sublattices coupled with π/2 rotation leads to a spin-polarized band structure in the antiferromagnetic state, which gives rise to a d-wave modulation of the Fermi surface in the spin-triplet channel. We argue a finite spin conductivity that changes sign in the ab plane is expected in RuO2 because of this band structure. We analyze the origin of the antiferromagnetic instability and link it to presence of a nodal line close to the Fermi level.