Spontaneous Fermi Surface Deformation in the Three-Band Hubbard Model: A Variational Monte Carlo Study

We perform a variational Monte Carlo study of spontaneous d-waveform Fermi surface deformation (dFSD) within the three-band Hubbard model. It is found that the variational energy of a projected Fermi sea is reduced by introducing anisotropy between the hopping integrals along the x- and y-directions. Our results show that the dFSD state has the strongest tendency at half-filling in the absence of magnetism, and disappears as the hole concentration increases to n(h) approximate to 1.15. This is in qualitative agreement with the results of the mean field analysis and the exact diagonalization calculation for one-band models, and provides a qualitative explanation of the "intra-unit-cell" electronic nematicity revealed by scanning tunneling microscopy. An analysis of the dependences of dFSD on the parameters of the threeband model indicates that the copper on-site Coulomb interaction, nearest-neighbor copper-oxygen repulsion, and charge-transfer energy have marked positive effects on dFSD.