Competition between Pomeranchuk instabilities in the nematic and hexatic   channels in a two-dimensional spinless Fermi fluid
  We study the competition between the nematic and the hexatic phases of a two-dimensional spinless Fermi fluid near Pomeranchuk instabilities. We show that the general phase diagram of this theory contains a bicritical point where two second order lines and a first order nematic/hexatic phase transition meet together. We found that at criticality, and deep inside the associated symmetry broken phases, the low energy theory is governed by a dissipative cubic mode, even near the bicritical point where nematic and hexatic fluctuations cannot be distinguished due to very strong dynamical couplings. 
Daniel G. Barci, Marta Trobo, Victoria Fern\'andez, Luis E. Oxman