Route to ferromagnetism in organic polymers

TL;DR

This paper demonstrates theoretically that by tuning interactions in organic polymers, it is possible to induce flat bands leading to ferromagnetism or half-metallicity, offering a pathway for designing magnetic organic materials.

Contribution

It introduces a rigorous theoretical method to design organic polymers with flat bands and ferromagnetic properties through interaction tuning.

Findings

Interactions can induce flat bands in dispersive structures.

Pentagon chain polymers can become ferromagnetic above half filling.

Design principles for magnetic organic polymers are established.

Abstract

Employing a rigorous theoretical method for the construction of exact many-electron ground states we prove that interactions can be employed to tune a bare dispersive band structure such that it develops a flat band. Thereby we show that pentagon chain polymers with electron densities above half filling may be designed to become ferromagnetic or half metallic.