Emergence of $p+ip$ superconductivity in $2$D strongly correlated Dirac fermions

TL;DR

This paper theoretically discovers a $p+ip$ superconducting state coexisting with ferromagnetism in a honeycomb lattice Hubbard model at low doping, suggesting new mechanisms and pathways for experimental realization in strongly correlated systems.

Contribution

It introduces a novel $p+ip$ superconducting ground state in a strongly correlated lattice model using advanced tensor network and field theory methods.

Findings

$p+ip$ SC state coexists with ferromagnetism at low doping.

Small Zeeman field stabilizes the $p+ip$ SC state.

Potential realization in realistic materials proposed.

Abstract

Searching for $p+ip$ superconducting(SC) state has become a fascinating subject in condensed matter physics, as a dream application awaiting in topological quantum computation. In this paper, we report a theoretical discovery of a $p+ip$ SC ground state (coexisting with ferromagnetic order) in honeycomb lattice Hubbard model with infinite repulsive interaction at low doping($\delta< 0.2$), by using both the state-of-art Grassmann tensor product state(GTPS) approach and a quantum field theory approach. Our discovery suggests a new mechanism for $p+ip$ SC state in generic strongly correlated systems and opens a new door towards experimental realization. The $p+ip$ SC state has an instability towards a potential non-Fermi liquid with a large but finite $U$. However, a small Zeeman field term stabilizes the $p+ip$ SC state. Relevant realistic materials are also proposed.