Anisotropic Heisenberg Model on Core-Shell Structured Nanotube Geometry

TL;DR

This paper investigates how anisotropy in exchange interactions affects the critical temperature and order parameter of the Heisenberg model on a core-shell nanotube using effective field theory with a 4-spin cluster approximation.

Contribution

It introduces a 4-spin cluster effective field theory approach to analyze anisotropic Heisenberg nanotubes and assesses its accuracy for critical temperature predictions.

Findings

Critical temperature varies with exchange anisotropy.

Minimum 4-spin cluster is sufficient for accurate critical behavior.

Effective field theory is suitable for small Heisenberg nanotube systems.

Abstract

The effect of the anisotropy in the exchange interaction on the critical temperature and the order parameter of the anisotropic Heisenberg model on a core-shell structured nanotube geometry has been investigated. As a formulation, effective field theory with the differential operator technique and decoupling approximation within the 4-spin cluster (EFT-4) has been used. The variation of the critical temperature with the anisotropy in the exchange interaction has been obtained. Besides, suitability of the effective field theory in small clusters as a formulation for the Heisenberg nanotube has been discussed and it is concluded that minimum size of the cluster is 4-spin cluster, which can give the correct critical description of the system.