Kun Fang, Gayanath Fernando, Armen Kocharian
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 drives the nematic phase into a phase similar to the stripe structure. The local order parameter is defined based on local electronic transition rate. The spin (magnetic) correlation function is also calculated in momentum space and shows the effects from the real-space nematicity.
View original:
http://arxiv.org/abs/1205.2928
No comments:
Post a Comment