Superconductivity and intra-unit-cell electronic nematic phase in the three-band model of cuprates

TL;DR

This study investigates the emergence of intra-unit-cell electronic nematicity and superconductivity in a three-band model of cuprates, revealing that electron correlations can induce nematic phases without intersite oxygen interactions.

Contribution

It demonstrates that electron correlations alone can induce nematicity in the three-band cuprate model, and explores the coexistence of nematicity and superconductivity.

Findings

Nematic phase arises from electron correlations, not intersite oxygen interactions.

Doping induces a transfer of electron density from d- to p-orbitals during nematic transition.

Coexistence of nematicity and superconductivity occurs in certain doping regimes.

Abstract

The intra-unit-cell nematic phase is studied within the three-band Emery model of the cuprates with the use of the approach based on the diagrammatic expansion of the Gutzwiller wave function (DE-GWF). According to our analysis the spontaneous $C_4$ symmetry breaking of the electronic wave function, leading to the nematic behavior, can appear due to electron correlations induced mainly by the onsite Coulomb repulsion, even in the absence of the corresponding intersite oxygen-oxygen repulsion term. The latter has been considered as the triggering factor of the nematic state formation in a number of previous studies. Also, we show that, at the transition to the nematic phase electron concentration transfer from $d$- to $p$- orbitals takes place, apart from the usually discussed $p_x/p_y$ polarization. The determined stability regime of the nematic phase appears in the doping range similar to that of the paired phase, showing that both phases have a common origin, even though they compete. Also, we show that in a significant doping range a coexistence region of superconductivity and nematicity appears. The results are discussed in the view of the experimental findings considering the relation between nematicity and pseudogap behavior.