Impurity and boundary effects in one and two-dimensional inhomogeneous Heisenberg antiferromagnets

TL;DR

This paper develops a density-functional theory approach for inhomogeneous Heisenberg antiferromagnets, enabling the calculation of ground-state energies in complex nanomagnetic systems with impurities and boundary effects.

Contribution

It introduces a local-density approximation tailored for Heisenberg models, allowing analysis of impurity and boundary effects in various dimensions and spin magnitudes.

Findings

Successfully calculated ground-state energies for diverse inhomogeneous systems.

Demonstrated the method's ability to handle impurity and boundary effects.

Extended the applicability of density-functional theory to complex magnetic nanostructures.

Abstract

We calculate the ground-state energy of one and two-dimensional spatially inhomogeneous antiferromagnetic Heisenberg models for spins 1/2, 1, 3/2 and 2. Our calculations become possible as a consequence of the recent formulation of density-functional theory for Heisenberg models. The method is similar to spin-density-functional theory, but employs a local-density-type approximation designed specifically for the Heisenberg model, allowing us to explore parameter regimes that are hard to access by traditional methods, and to consider complications that are important specifically for nanomagnetic devices, such as the effects of impurities, finite-size, and boundary geometry, in chains, ladders, and higher-dimensional systems.