Eur. Phys. J. B (2014) 87: 267
https://doi.org/10.1140/epjb/e2014-50177-2

Regular Article

Correlation between quantum charge fluctuations and magnetic ordering in multiferroic LuFe₂O₄

Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, 87545 NM, USA

^a e-mail: rpprasan@lanl.gov

Received: 16 March 2014
Received in final form: 19 August 2014
Published online: 10 November 2014

Abstract

We examine the interplay between quantum charge fluctuations and magnetic ordering in multiferroic LuFe₂O₄ and show that this can couple spin and charge degrees of freedom in a LuFe₂O₄ bilayer below the Neel temperature T_N. Our analysis supports the idea that the double exchange mechanism normally used in metallic systems can be applied to charge-ordered insulators. This causes ferrimagnetic spin order to reduce the transfer integrals between Fe²⁺ and Fe³⁺ in LuFe₂O₄, decreasing charge fluctuations and increasing the polarization in this system below T_N. This work thus provides a more detailed understanding of the mechanism for spin-charge coupling in LuFe₂O₄.