Random Frustration in two-dimensional spin-1/2 Heisenberg antiferromagnet

Abstract

The square lattice spin-1/2 antiferromagnet containing a dilute concentration, $\delta$, of randomly placed ferromagnetic nearest-neighbor bonds is studied at low-temperature via non-linear $\sigma$-model techniques and by exact diagonalization. We generally find that long-range N\' eel order is destroyed above a critical strength in the defective ferromagnetic exchange coupling-constant given by $|K_c|/J\sim {\delta }^{-1/2}$. We also observe large statistical fluctuations both in the spin-stiffness and in the antiferromagnetic structure-factor near this critical point, suggesting the onset of a spin-glass phase.

13 pgs, TeX, submitted to Phys. Rev. Feb. 22, 1994. (Correct set of figures follow)

References in corpus (5)

• Gapless Spin-Fluid Ground State in a Random Quantum Heisenberg Magnet
• Universal quantum critical dynamics of two-dimensional antiferromagnets
• Toward a Unified Magnetic Phase Diagram of the Cuprate Superconductors
• Universal Magnetic Properties of $L{a}_{2-\delta }S{r}_{\delta }Cu{O}_4$ at Intermediate Temperatures
• Direct Calculation of Spin-Stiffness for Spin-1/2 Heisenberg Models

Cited by in corpus (5)

• Quantum Phase Transitions of a Square-Lattice Heisenberg Antiferromagnet with Two Kinds of Nearest-Neighbour Bonds: A High-Order Coupled-Cluster Treatment
• Square-lattice Heisenberg antiferromagnet with two kinds of nearest-neighbor regular bonds
• Local magnetic impurities in the 2D quantum Heisenberg antiferromagnet
• Metallic Surface Reconstruction Driven by Frustrated Antiferromagnetism
• Bond-disordered spin systems: Theory and application to doped high-Tc compounds