Spin Density Wave Fluctuations and p-Wave Pairing in Sr2RuO4

Recently, a debate has arisen over which of the two distinct parts of the Fermi surface of Sr2RuO4 is the active part for the chiral p-wave superconductivity exhibited. Early theories proposed p-wave pairing on the two-dimensional gamma band, whereas a recent proposal focuses on the one-dimensional (alpha, beta) bands whose nesting pockets are the source of the strong incommensurate spin density wave (SDW) fluctuations. We apply a renormalization group theory to study quasi-one-dimensional repulsive Hubbard chains and explain the form of SDW fluctuations, reconciling the absence of long-range order with their nesting Fermi surface. The mutual exclusion of p-wave pairing and SDW fluctuations in repulsive Hubbard chains favors the assignment of the two-dimensional gamma band as the source of p-wave pairing. DOI: 10.1103/PhysRevLett.110.167003