Phase Diagram of a Frustrated Quantum Antiferromagnet on the Honeycomb Lattice: Magnetic Order versus Valence-Bond Crystal formation

Details Phase Diagram of a Frustrated Quantum Antiferromagnet on the Honeycomb Lattice: Magnetic Order versus Valence-Bond Crystal formation Phase Diagram of a Frustrated Quantum Antiferromagnet on the Honeycomb Lattice: Magnetic Order versus Valence-Bond Crystal formation

2011-02-25

arxiv.org/abs/1102.5325v3

Phys. Rev. B 84, 024406 (2011)

Physics

Condensed Matter

Strongly Correlated Electrons

23 pages, 24 figures, (v2) expanded discussion of staggered dimer correlations at large J2, (v3) new figure with dimer correla

Scientific paper

10.1103/PhysRevB.84.024406

We present a comprehensive computational study of the phase diagram of the frustrated S=1/2 Heisenberg antiferromagnet on the honeycomb lattice, with second-nearest (J2) and third-neighbor (J3) couplings. Using a combination of exact diagonalizations of the original spin model, of the Hamiltonian projected into the nearest neighbor short range valence bond basis, and of an effective quantum dimer model, as well as a self-consistent cluster mean-field theory, we determine the boundaries of several magnetically ordered phases in the region J2,J3\in [0,1], and find a sizable magnetically disordered region in between. We characterize part of this magnetically disordered phase as a plaquette valence bond crystal phase. At larger J2, we locate a sizable region in which staggered valence bond crystal correlations are found to be important, either due to genuine valence bond crystal ordering or as a consequence of magnetically ordered phases which break lattice rotational symmetry. Furthermore we find that a particular parameter-free Gutzwiller projected tight-binding wave function has remarkably accurate energies compared to finite-size extrapolated ED energies along the transition line from conventional N\'eel to plaquette VBC phases, a fact that points to possibly interesting critical behavior - such as a deconfined critical point - across this transition. We also comment on the relevance of this spin model to model the spin liquid region found in the half-filled Hubbard model on the honeycomb lattice.

Affiliated with

Also associated with

No associations

Rating

Phase Diagram of a Frustrated Quantum Antiferromagnet on the Honeycomb Lattice: Magnetic Order versus Valence-Bond Crystal formation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Phase Diagram of a Frustrated Quantum Antiferromagnet on the Honeycomb Lattice: Magnetic Order versus Valence-Bond Crystal formation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phase Diagram of a Frustrated Quantum Antiferromagnet on the Honeycomb Lattice: Magnetic Order versus Valence-Bond Crystal formation will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-301562