6533b861fe1ef96bd12c4452

RESEARCH PRODUCT

Quantum gap and spin-wave excitations in the Kitaev model on a triangular lattice

George JackeliGeorge JackeliAndrea Di CioloAdolfo Avella

subject

Frustrated magnetismFOS: Physical sciencesBond-dependent Ising couplingsQuantum fluctuations01 natural sciencesTriangular lattice010305 fluids & plasmasCondensed Matter - Strongly Correlated ElectronsSpin waveQuantum mechanics0103 physical sciencesSpin gapHexagonal latticeElectrical and Electronic Engineering010306 general physicsQuantumQuantum fluctuationSpin-½PhysicsCondensed matter physicsStrongly Correlated Electrons (cond-mat.str-el)Condensed Matter PhysicsElectronic Optical and Magnetic MaterialsBond-dependent Ising couplings; Frustrated magnetism; Linear spin-wave spectrum; Quantum fluctuations; Spin gap; Triangular lattice;Ising modelGround stateDegeneracy (mathematics)Linear spin-wave spectrum

description

We study the effects of quantum fluctuations on the dynamical generation of a gap and on the evolution of the spin-wave spectra of a frustrated magnet on a triangular lattice with bond-dependent Ising couplings, analog of the Kitaev honeycomb model. The quantum fluctuations lift the subextensive degeneracy of the classical ground-state manifold by a quantum order-by-disorder mechanism. Nearest-neighbor chains remain decoupled and the surviving discrete degeneracy of the ground state is protected by a hidden model symmetry. We show how the four-spin interaction, emergent from the fluctuations, generates a spin gap shifting the nodal lines of the linear spin-wave spectrum to finite energies.

yearjournalcountryeditionlanguage
2017-11-06
10.1016/j.physb.2017.10.024http://arxiv.org/abs/1711.02016