Local electronic nematicity in the one-band Hubbard model

TL;DR

This paper demonstrates that the two-dimensional Hubbard model can exhibit local electronic nematicity, supporting experimental observations of rotational symmetry breaking in high-temperature superconductors, and explores how this nematic phase varies with electron filling.

Contribution

It provides theoretical evidence for local electronic nematicity in the Hubbard model using the variational cluster approach, linking it to experimental findings in cuprate superconductors.

Findings

Nematic phase identified in the overdoped region.

Local nematicity decreases with increasing electron filling.

Strong Coulomb interaction may induce stripe-like phases.

Abstract

Nematicity is a well known property of liquid crystals and has been recently discussed in the context of strongly interacting electrons. An electronic nematic phase has been seen by many experiments in certain strongly correlated materials, in particular, in the pseudogap phase generic to many hole-doped cuprate superconductors. Recent measurements in high $T_c$ superconductors has shown even if the lattice is perfectly rotationally symmetric, the ground state can still have strongly nematic local properties. Our study of the two-dimensional Hubbard model provides strong support of the recent experimental results on local rotational $C_4$ symmetry breaking. The variational cluster approach is used here to show the possibility of an electronic nematic state and the proximity of the underlying symmetry-breaking ground state within the Hubbard model. We identify this nematic phase in the overdoped region and show that the local nematicity decreases with increasing electron filling. Our results also indicate that strong Coulomb interaction may drive the nematic phase into a phase similar to the stripe structure. The calculated spin (magnetic) correlation function in momentum space shows the effects resulting from real-space nematicity.