Rashba spin-orbit coupling in the square-lattice Hubbard model: A truncated-unity functional renormalization group study

The Rashba-Hubbard model on the square lattice is the paradigmatic case for studying the effect of spin-orbit coupling, which breaks spin and inversion symmetry, in a correlated electron system. We employ a truncatedunity variant of the functional renormalization group which allows us to analyze magnetic and superconducting instabilities on equal footing. We derive phase diagrams depending on the strengths of Rasbha spin-orbit coupling, real second-neighbor hopping, and electron filling. We find commensurate and incommensurate magnetic phases which compete with d-wave superconductivity. Due to the breaking of inversion symmetry, singlet and triplet components mix; we quantify the mixing of d-wave singlet pairing with f-wave triplet pairing.

Automated summary

We study the Rashba-Hubbard model on the square lattice, which is a typical case for studying spin-orbit coupling effects in correlated electron systems. Using a truncatedunity variant of the functional renormalization group, we analyze magnetic and superconducting instabilities simultaneously. Phase diagrams are derived based on the strengths of Rasbha spin-orbit coupling, real second-neighbor hopping, and electron filling. Both commensurate and incommensurate magnetic phases are found to compete with d-wave superconductivity. Mixing of d-wave singlet pairing with f-wave triplet pairing is quantified due to the breaking of inversion symmetry.