Thermodynamics of two-dimensional spin models with bimodal random-bond disorder

TL;DR

This paper employs numerical linked cluster expansions to analyze thermodynamic properties of two-dimensional spin models with bimodal random-bond disorder, providing insights into disorder effects on energy, entropy, specific heat, and susceptibility.

Contribution

It introduces a numerical approach to study thermodynamics of disordered 2D spin models and derives analytic expressions for low-temperature expansions.

Findings

Disorder affects thermodynamic quantities compared to clean models.

Analytic low-temperature expansions are obtained.

Results are consistent across square and honeycomb lattices.

Abstract

We use numerical linked cluster expansions to study thermodynamic properties of the two-dimensional spin-1/2 Ising, XY, and Heisenberg models with bimodal random-bond disorder on the square and honeycomb lattices. In all cases, the nearest-neighbor coupling between the spins takes values $\pm J$ with equal probability. We obtain the disorder averaged (over all disorder configurations) energy, entropy, specific heat, and uniform magnetic susceptibility in each case. These results are compared with the corresponding ones in the clean models. Analytic expressions are obtained for low orders in the expansion of these thermodynamic quantities in inverse temperature.