Interplay between parallel and diagonal electronic nematic phases in   interacting systems
  An electronic nematic phase can be classified by a spontaneously broken discrete rotational symmetry of a host lattice. In a square lattice, there are two distinct nematic phases. The parallel nematic phase breaks $x$ and $y$ symmetry, while the diagonal nematic phase breaks the diagonal $(x+y)$ and anti-diagonal $(x-y)$ symmetry. We investigate the interplay between the parallel and diagonal nematic orders using mean field theory. We found that the nematic phases compete with each other, while they coexist in a finite window of parameter space. The quantum critical point between the diagonal nematic and isotropic phases exists, and its location in a phase diagram depends on the topology of the Fermi surface. We discuss the implication of our results in the context of neutron scattering and Raman spectroscopy measurements on La$_{2-x}$Sr$_x$CuO$_4$. 
Hyeonjin Doh, Nir Friedman, Hae-Young Kee