Chiral d-wave Superconductivity in a Triangular Surface Lattice Mediated by Long-range Interaction

TL;DR

This paper investigates chiral d-wave superconductivity in a triangular lattice model with long-range interactions, revealing a novel phase driven by charge and spin fluctuations in doped ad-atom systems.

Contribution

It introduces a single band model with 1/r long-range interactions and employs the TRILEX method to identify unconventional superconductivity in this context.

Findings

Discovery of chiral d-wave superconductivity in the model.

Superconductivity driven by both charge and spin fluctuations.

Enhancement of pairing due to long-range interactions.

Abstract

Correlated ad-atom systems on the Si(111) surface have recently attracted an increased attention as strongly correlated systems with a rich phase diagram. We study these materials by a single band model on the triangular lattice including 1/r long-range interaction. Employing the recently proposed TRILEX method we find an unconventional superconducting phase of chiral d-wave symmetry in hole-doped systems. The superconductivity is driven simultaneously by both charge and spin fluctuations and is strongly enhanced by the long-range tail of the interaction. We provide an analysis of the relevant collective bosonic modes and explain how in triangular symmetry both charge and spin channels contribute to the Cooper-pairing.