Frustration effects in magnetic molecules

TL;DR

This study uses exact diagonalization to explore how frustration affects the ground state and low-temperature properties of Heisenberg antiferromagnets on specific magnetic molecules, revealing unique magnetization and heat capacity behaviors.

Contribution

It provides detailed insights into the quantum and frustration effects in magnetic molecules using exact diagonalization, focusing on the cuboctahedron and icosidodecahedron structures.

Findings

Frustration causes significant changes in spin correlations.

Unique magnetization processes at low temperatures.

Presence of low-lying non-magnetic excitations affecting specific heat.

Abstract

By means of exact diagonalization we study the ground-state and the low-temperature physics of the Heisenberg antiferromagnet on the cuboctahedron and the icosidodecahedron. Both are frustrated magnetic polytopes and correspond to the arrangement of magnetic atoms in the magnetic molecules Cu12La8 and Mo72Fe30. The interplay of strong quantum fluctuations and frustration influences the ground state spin correlations drastically and leads to an interesting magnetization process at low temperatures. Furthermore the frustration yields low-lying non-magnetic excitations resulting in an extra low-temperature peak in the specific heat.