Two-dimensional spin-1/2 Heisenberg antiferromagnet: A quantum Monte Carlo study
- Department of Physics, California Institute of Technology, Pasadena, California 91125 (US)
Spin-1/2 nearest-neighbor Heisenberg antiferromagnet on a square lattice is studied via a large-scale quantum Monte Carlo simulation. We developed a fast and efficient multispin coding algorithm on a parallel supercomputer, based on the Suzuki-Trotter transformation. We performed high-statistics simulations on lattices as large as 128{times}128 spins, in the temperature range from 0.25{ital J} to 2.5{ital J}. We calculated energy, specific heat, uniform and staggered susceptibility, and staggered correlation function, from which we deduce the correlation length. For temperatures higher than {ital J}, the results are in excellent agreement with high-temperature series expansion. At low temperatures the long-wavelength behavior is essentially classical. Our data show that the correlation length and staggered susceptibility are quantitatively well described by the renormalized classical picture at the two-loop level of approximation. From the divergence of correlation length, we deduce the value of quantum-renormalized spin stiffness, {rho}{sub {ital s}}/{ital J}=0.199(2). We give evidence that the correlation function is of Ornstein-Zernike type. By comparing the largest measured correlation lengths with neutron scattering experiments on La{sub 2}CuO{sub 4}, we deduce the value of effective exchange coupling {ital J}=1450{plus minus}30 K.
- DOE Contract Number:
- FG03-85ER25009
- OSTI ID:
- 5752001
- Journal Information:
- Physical Review, B: Condensed Matter; (USA), Vol. 43:4; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIFERROMAGNETIC MATERIALS
HEISENBERG MODEL
COHERENCE LENGTH
CORRELATION FUNCTIONS
ENERGY
MAGNETIC SUSCEPTIBILITY
MONTE CARLO METHOD
NEUTRON DIFFRACTION
SPECIFIC HEAT
TEMPERATURE DEPENDENCE
TWO-DIMENSIONAL CALCULATIONS
COHERENT SCATTERING
CRYSTAL MODELS
DIFFRACTION
DIMENSIONS
FUNCTIONS
LENGTH
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MATERIALS
MATHEMATICAL MODELS
PHYSICAL PROPERTIES
SCATTERING
THERMODYNAMIC PROPERTIES
656002* - Condensed Matter Physics- General Techniques in Condensed Matter- (1987-)