Theory of the spin liquid state of the Heisenberg antiferromagnet

Journal Article · Thu Jun 01 00:00:00 EDT 1989 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.39.11879· OSTI ID:6257492

Kalmeyer, V; Laughlin, R B

We propose that the disordered state of a two-dimensional spin-1/2 Heisenberg antiferromagnet is physically equivalent to the incompressible liquid state of the fractional quantum Hall system. The fractional quantum Hall state for bosons is shown to be an exact spin singlet and to possess a low variational energy for the near-neighbor Heisenberg model on a triangular lattice. Variational wave functions for neutral spin-1/2 excitations are constructed and shown to form an exact spin doublet. Variational energies of these states are calculated, and their spin density profiles are determined. We find that a localized spin-1/2 quaisparticle has a size comparable to a lattice bond length and an excitation energy ..delta..=1.3/ital J/. The energy-momentum dispersion of quasiparticles and spin-1 collective modes, obtained variationally, supports the hypothesis that the spin liquid state has a finite energy gap. The 1/2 fractional statistics exhibited by the quasiparticle excitations is explicitly demonstrated.

• Research Organization: Department of Physics, Stanford University, Stanford, California 94305(US); Department of Physics, Stanford University, Stanford, California 94305; Lawrence Livermore Laboratory, University of California, Livermore, California 94550
• OSTI ID: 6257492
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 39:16; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANGULAR MOMENTUM
ANTIFERROMAGNETIC MATERIALS
CRYSTAL MODELS
ENERGY GAP
FUNCTIONS
HALL EFFECT
HEISENBERG MODEL
MAGNETIC MATERIALS
MATERIALS
MATHEMATICAL MODELS
PARTICLE PROPERTIES
QUASI PARTICLES
SPIN
TEMPERATURE DEPENDENCE
WAVE FUNCTIONS