Weakly frustrated spin-1/2 Heisenberg antiferromagnet in two dimensions: Thermodynamic parameters and the stability of the Neel state

Journal Article · Mon Jun 01 00:00:00 EDT 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.45.13121· OSTI ID:7182674

Einarsson, T; Froejdh, P; Johannesson, H ^[1]

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1. Institute of Theoretical Physics, Chalmers University of Technology, S-412 96 Goeteborg (Sweden)

Using a Schwinger-boson mean-field theory, we calculate the low-temperature uniform transverse susceptibility {chi}{sub {perpendicular}} and spin-wave velocity {ital c} for the weakly frustrated spin-1/2 square-lattice Heisenberg antiferromagnet with exchange couplings {ital J}{sub 1}, {ital J}{sub 2}, and {ital J}{sub 3} to first, second, and third neighbors. By connecting {chi}{sub {perpendicular}} and {ital c} to the bare coupling of the nonlinear {sigma} model that describes the long-wavelength limit of the antiferromagnet, we are able to improve upon earlier renormalization-group estimates of the zero-temperature phase boundary separating Neel and magnetically disordered ground states. To one-loop level in an {epsilon} expansion we find a disordering transition across a line joining the points ({ital J}{sub 2},{ital J}{sub 3})/{ital J}{sub 1}=(0.15,0) and (0,0.09). Thus, the classical phase boundary ({ital J}{sub 2}+2{ital J}{sub 3})/{ital J}{sub 1}=1/2 is shifted asymmetrically by quantum fluctuations, as expected when the transition is to a columnar dimerized ground state.

• OSTI ID: 7182674
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 45:22; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
HEISENBERG MODEL
MAGNETIC SUSCEPTIBILITY
HIGH-TC SUPERCONDUCTORS
ANTIFERROMAGNETISM
MEAN-FIELD THEORY
SIGMA MODEL
SPIN WAVES
BOSON-EXCHANGE MODELS
CRYSTAL MODELS
MAGNETIC PROPERTIES
MAGNETISM
MATHEMATICAL MODELS
PARTICLE MODELS
PERIPHERAL MODELS
PHYSICAL PROPERTIES
SUPERCONDUCTORS
665411* - Basic Superconductivity Studies- (1992-)