Broken translational symmetry in an emergent paramagnetic phase of   graphene
  We show that the spin-density wave state on the partially filled honeycomb and triangular lattices is preempted by a paramagnetic phase that breaks an emergent Z_4 symmetry of the system, associated with the four inequivalent arrangements of spins in the quadrupled unit cell. Unlike other emergent paramagnetic phases in itinerant and localized-spin systems, this state preserves the rotational symmetry of the lattice but breaks its translational symmetry, giving rise to a super-lattice structure that can be detected by scanning tunneling microscopy. This emergent phase also has distinctive signatures in the magnetic spectrum that can be probed experimentally. 
Gia-Wei Chern, Rafael M. Fernandes, Rahul Nandkishore, Andrey V.   Chubukov
cond-mat.str-el cond-mat.mes-hall