Pentagon chain in external fields

TL;DR

This paper studies how external magnetic and electric fields qualitatively alter the electronic and magnetic properties of a pentagon chain Hubbard model, leading to changes in band structure and magnetic phases.

Contribution

It demonstrates, in a non-approximated way, the impact of external fields on the system's band structure and magnetic phase domains, including ferromagnetic ground states.

Findings

External magnetic fields modify the band structure.

External electric potentials influence ordered phase domains.

Ferromagnetic ground states emerge under external fields.

Abstract

We consider a pentagon chain described by a Hubbard type of model considered under periodic boundary conditions. The system i) is placed in an external magnetic field perpendicular to the plane of the cells, and ii) is in a site selective manner under the action of an external electric potential. In these conditions we show in a non-approximated manner that the physical properties of the system can be qualitatively changed. The changes cause first strong modifications of the band structure of the system created by the one-particle part of the Hamiltonian, and second, considerably redraw the emergence domains of ordered phases. We exemplify this by deducing ferromagnetic ground states in the presence of external fields in two different domains of the parameter space.