Broken translational symmetry in an emergent paramagnetic phase of graphene

• Main Authors: Chern, Gia-Wei (Author), Fernandes, Rafael M. (Author), Nandkishore, Rahul Mahajan (Contributor), Chubukov, Andrey V. (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2012-12-18T15:00:37Z.
• Subjects: Article
• Online Access: Get fulltext

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[subscript 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 C[subscript 6] rotational symmetry of the lattice, but breaks its translational symmetry, giving rise to a superlattice 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.
ICAM (Grant NSF-DMR 0645461)
National Science Foundation (U.S.) (Partnerships for International Research and Education Program OISE-0968226)