Magnetic order and spin excitations in layered Heisenberg antiferromagnets with compass-model anisotropies

Abstract

The spin-wave excitation spectrum, the magnetization, and the Néel temperature for the quasi-two-dimensional spin-1/2 antiferromagnetic Heisenberg model with compass-model interaction in the plane proposed for iridates are calculated in the random phase approximation. The spin-wave spectrum agrees well with data of Lanczos diagonalization. We find that the Neel temperature is enhanced by the compass-model interaction and is close to the experimental value for Ba2IrO4.

6 pages, 6 figures, 4 references and one figure are added in the second version

References in corpus (6)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Robustness of basal-plane antiferromagnetic order and the $J_{eff}=1/2$ state in single-layer iridate spin-orbit Mott insulators
• First order phase transition in the anisotropic quantum orbital compass model
• Monte Carlo simulations of the directional-ordering transition in the two-dimensional classical and quantum compass model
• Re-examining the directional-ordering transition in the compass model with screw-periodic boundary conditions
• Computation of the temperature dependence of the heat capacity of complex molecular systems using random color noise