Correlations in Novel Quantum Materials 2023 (CNQM2023)

Spin and Charge Fluctuation Induced Order in ABCB Tetralayer Graphene

24 Jul 2023, 16:45

2h 45m

2D5 (MPI-FKF)

Contributed Poster Poster Session

Speaker

Lennart Klebl (I. Institute for Theoretical Physics, Universität Hamburg, Notkestraße 9-11, 22607 Hamburg, Germany)

Description

Motivated by the recent experimental realization of ABCB stacked quadlayer graphene [Wirth et al., ACS Nano 16, 16617 (2022)], we study correlated phenomena in moiré-less graphene tetralayers for realistic interaction profiles using an orbital resolved, weak coupling random phase approximation approach. We demonstrate that spin fluctuations originating from local interactions are crucial close to the van-Hove singularities on the electron- and hole-doped side promoting orbitally selective ferrimagnetic spin alignments. Magnetic fluctuations around these correlated states enhance unconventional spin-triplet, valley-singlet superconductivity with $f$-wave symmetry due to intervalley scattering. Charge fluctuations arising from long-ranged Coulomb interactions promote doubly degenerate $p$-wave superconductivity close to the van Hove singularities. At the conduction band edge of ABCB graphene, we find that both spin and charge fluctuations drive $f$-wave superconductivity. Our analysis suggests strong competition between superconducting states emerging from long- and short-ranged Coulomb interactions and thus stresses the importance of microscopically derived interaction profiles to make reliable predictions for the origin of superconductivity in graphene based (moiré-less) heterostructures.