title: Deconfined criticality in the frustrated Heisenberg honeycomb antiferromagnet.
abstract: Using the density matrix renormalization group, we determine the phase diagram of the spin-1/2 Heisenberg antiferromagnet on a honeycomb lattice with a nearest-neighbor interaction J(1) and a frustrating, next-nearest-neighbor exchange J(2). As frustration increases, the ground state exhibits Néel, plaquette, and dimer orders, with critical points at J(2)/J(1) = 0.22 and 0.35. We observe that both the spin gap and the corresponding order parameters vanish continuously at both the critical points, indicating the presence of deconfined quantum criticality.
authors.affiliation: Institute for Theoretical Solid State Physics, IFW Dresden, PF 270116, D-01171 Dresden, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Ganesh
authors.affiliation: Institute for Theoretical Solid State Physics, IFW Dresden, PF 270116, D-01171 Dresden, Germany and Department of Physics, Technical University Dresden, D-1062 Dresden, Germany.
authors.forename: Jeroen
authors.initials: J
authors.lastname: van den Brink
authors.affiliation: Institute for Theoretical Solid State Physics, IFW Dresden, PF 270116, D-01171 Dresden, Germany.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nishimoto