TY - JOUR

T1 - Neutron-scattering cross section of the S=1/2 Heisenberg triangular antiferromagnet

AU - Lefmann, K.

AU - Hedegård, P.

PY - 1994

Y1 - 1994

N2 - In this paper we use a Schwinger-boson mean-field approach to calculate the neutron-scattering cross section from the S = 1/2 antiferromagnet with nearest-neighbor isotropic Heisenberg interaction on a two-dimensional triangular lattice. We investigate two solutions for T = 0: (i) a state with long-range order resembling the Neel state and (ii) a resonating valence bond or ''spin liquid'' state with an energy gap, E(g) almost-equal-to 0.17J, for the elementary excitations (spinons). For solution (ii) the neutron cross section shows Bragg rods at kappa = K = (1/3, 1/3), whereas solution (ii) shows no elastic, but a set of broader dispersive spin excitations around kappa almost-equal-to (1/2, 0) and around kappa almost-equal-to (1/3, 1/3) for omega/E(g) = 2.5-4. It should thus be possible to distinguish these two states in a neutron-scattering experiment.

AB - In this paper we use a Schwinger-boson mean-field approach to calculate the neutron-scattering cross section from the S = 1/2 antiferromagnet with nearest-neighbor isotropic Heisenberg interaction on a two-dimensional triangular lattice. We investigate two solutions for T = 0: (i) a state with long-range order resembling the Neel state and (ii) a resonating valence bond or ''spin liquid'' state with an energy gap, E(g) almost-equal-to 0.17J, for the elementary excitations (spinons). For solution (ii) the neutron cross section shows Bragg rods at kappa = K = (1/3, 1/3), whereas solution (ii) shows no elastic, but a set of broader dispersive spin excitations around kappa almost-equal-to (1/2, 0) and around kappa almost-equal-to (1/3, 1/3) for omega/E(g) = 2.5-4. It should thus be possible to distinguish these two states in a neutron-scattering experiment.

KW - Materialer med særlige fysiske og kemiske egenskaber

U2 - 10.1103/PhysRevB.50.1074

DO - 10.1103/PhysRevB.50.1074

M3 - Journal article

VL - 50

SP - 1074

EP - 1083

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 1098-0121

IS - 2

ER -