Alladi Ramakrishnan Hall

Frustrated magnetism on the honeycomb lattice

Ganesh Ramachandran

Institute for Theoretical Solid State Physics, Dresden

Frustrated magnetism gives rise to many body states with various
levels of entanglement. Recently, such a novel state consisting of entangled
plaquettes has been proposed in the honeycomb lattice J1-J2 model. We use
DMRG calculations, supported by semi-analytical methods, to study the ground
state of this model.
We find three phases as we vary J2, viz., Neel order, weak plaquette order
and dimer order. The plaquette state has f-wave symmetry and breaks
translational symmetry. We use a plaquette-operator approach to obtain an
effective description of this state and its low lying excitations.