Frustration effects in magnetic molecules

TL;DR

This paper explores how magnetic molecules, especially frustrated spin systems, exhibit unique quantum phenomena such as giant magnetization jumps, phase transitions, and enhanced magnetocaloric effects, advancing understanding of condensed matter physics in zero dimensions.

Contribution

It demonstrates the impact of molecular magnetism on frustrated spin systems, revealing new quantum effects and deviations from expected behaviors in low-energy spectra.

Findings

Localized magnons cause giant magnetization jumps

Frustration induces metamagnetic phase transitions without anisotropy

Enhanced magnetocaloric effect observed in frustrated magnetic molecules

Abstract

Besides being a fascinating class of new materials, magnetic molecules provide the opportunity to study concepts of condensed matter physics in zero dimensions. This contribution will exemplify the impact of molecular magnetism on concepts of frustrated spin systems. We will discuss spin rings and the unexpected rules that govern their low-energy behavior. Rotational bands, which are experimentally observed in various molecular magnets, provide a useful, simplified framework for characterizing the energy spectrum, but there are also deviations thereof with far-reaching consequences. It will be shown that localized independent magnons on certain frustrated spin systems lead to giant magnetization jumps, a new macroscopic quantum effect. In addition a frustration-induced metamagnetic phase transitions will be discussed, which demonstrates that hysteresis can exist without anisotropy. Finally, it is demonstrated that frustrated magnetic molecules could give rise to an enhanced magnetocaloric effect.