Theory of two-dimensional quantum Heisenberg antiferromagnets with a nearly critical ground state

Journal Article · Sun May 01 04:00:00 EDT 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.49.11919· OSTI ID:7206591

Chubukov, A V ^[1]; Sachdev, S; Ye, J ^[2]

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1. Departments of Physics and Applied Physics, P.O. Box 208120, Yale University, New Haven, Connecticut 06520-8120 (United States) P. L. Kapitza Institute for Physical Problems, Moscow (Russian Federation)
2. Deparment of Physics and Applied Physics, P.O. Box 208120, Yale University, New Haven, Connecticut 06520-8120 (United States)

We present the general theory of clean, two-dimensional, quantum Heisenberg antiferromagnets which are close to the zero-temperature quantum transition between ground states with and without long-range Neel order. While some of our discussion is more general, the bulk of our theory will be restricted to antiferromagnets in which the Neel order is described by a three-vector order parameter. For Neel-ordered states, nearly critical'' means that the ground-state spin stiffness, [rho][sub [ital s]], satisfies [rho][sub [ital s]][much lt][ital J], where [ital J] is the nearest-neighbor exchange constant, while nearly critical'' quantum-disordered ground states have an energy gap, [Delta], towards excitations with spin 1, which satisfies [Delta][much lt][ital J]. The allowed temperatures, [ital T], are also smaller than [ital J], but [ital no] restrictions are placed on the values of [ital k][sub [ital B]][ital T]/[rho][sub [ital s]] or [ital k][sub [ital B]][ital T]/[Delta]. Under these circumstances, we show that the wave vector and/or frequency-dependent uniform and staggered spin susceptibilities, and the specific heat, are completely universal functions of just three thermodynamic parameters. On the ordered side, these three parameters are [rho][sub [ital s]], the [ital T]=0 spin-wave velocity [ital c], and the ground-state staggered moment [ital N][sub 0]; previous works have noted the universal dependence of the susceptibilities on these three parameters only in the more restricted regime of [ital k][sub [ital B]][ital T][much lt][rho][sub [ital s]]. On the disordered side the three thermodynamic parameters are [Delta], [ital c], and the spin-1 quasiparticle residue [ital scrA]. Explicit results for the universal scaling functions are obtained by a 1/[ital N] expansion on the [ital O]([ital N]) quantum nonlinear [sigma] model, and by Monte Carlo simulations. These calculations lead to a variety of testable predictions..

• OSTI ID: 7206591
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 49:17; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIFERROMAGNETISM
CALCULATION METHODS
COMPUTERIZED SIMULATION
COPPER COMPOUNDS
CRYSTAL MODELS
CUPRATES
ENERGY LEVELS
GROUND STATES
HEISENBERG MODEL
HIGH-TC SUPERCONDUCTORS
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MAGNETISM
MATHEMATICAL MODELS
MONTE CARLO METHOD
ORDER-DISORDER TRANSFORMATIONS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
SIMULATION
SPECIFIC HEAT
SPIN WAVES
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS