Quantum and thermal effects in the double exchange ferromagnet

TL;DR

This paper introduces a new analytical method to accurately evaluate quantum and thermal fluctuations in the double exchange ferromagnet, addressing limitations of classical models and better aligning with experimental observations.

Contribution

A novel analytical approach for systematically analyzing quantum and thermal effects in the double exchange ferromagnet.

Findings

Improved understanding of quantum fluctuations in ferromagnetic phases.

Enhanced modeling of thermal effects on magnetic properties.

Better agreement with experimental data on manganites.

Abstract

The physics of the ferromagnetic phase of the ``double exchange'' model has been widely discussed in the context of the CMR manganites. Usually, the double exchange ferromagnet is treated is classically, by mapping it onto an effective Heisenberg model. However this mapping does not permit a correct treatment of quantum or thermal fluctuation effects, and the results obtained lack many of the interesting features seen in experiments on the manganites. Here we outline a new analytic approach to systematically evaluating quantum and thermal corrections to the magnetic and electronic properties of the double exchange ferromagnet.