Chiral superconductivity in the doped triangular-lattice Fermi-Hubbard model in two dimensions

TL;DR

This paper uses advanced quantum Monte Carlo simulations to provide evidence of chiral superconductivity in the doped two-dimensional triangular-lattice Fermi-Hubbard model, revealing long-range order and phase transitions.

Contribution

It demonstrates the emergence of chiral superconductivity in the doped triangular-lattice Fermi-Hubbard model using state-of-the-art simulations, advancing understanding of frustrated strongly correlated systems.

Findings

Evidence of chiral superconductivity with long-range order.

Identification of phase transitions from metallic to insulating and magnetic states.

Support for the existence of chiral order parameters in the doped system.

Abstract

The triangular-lattice Fermi-Hubbard model has been extensively investigated in the literature due to its connection to chiral spin states and unconventional superconductivity. Previous simulations of the ground state of the doped system rely on quasi-one-dimensional lattices where true long-range order is forbidden. Here we simulate two-dimensional and quasi-one-dimensional triangular lattices using state-of-the-art Auxiliary-Field Quantum Monte Carlo. Upon doping a non-magnetic chiral spin state, we observe evidence of chiral superconductivity supported by long-range order in Cooper-pair correlation and a finite value of the chiral order parameter. With this aim, we first locate the transition from the metallic to the non-magnetic insulating phase and the onset of magnetic order. Our results pave the way towards a better understanding of strongly correlated lattice systems with magnetic frustration.