A Real Space Description of Magnetic Field Induced Melting in the Charge Ordered Manganites: I. The Clean Limit

TL;DR

This paper investigates how magnetic fields induce melting of charge order in clean half-doped manganites using real space Monte Carlo simulations, revealing hysteresis, inhomogeneous high conductance states, and phase separation phenomena.

Contribution

It provides a detailed real space analysis of magnetic field-induced charge order melting in clean manganites, incorporating multiple interactions and exploring phase behavior.

Findings

Hysteresis observed in charge order melting and recovery.

High conductance state can be spatially inhomogeneous without disorder.

Field-driven phase separation occurs during melting process.

Abstract

We study the melting of charge order in the half doped manganites using a model that incorporates double exchange, antiferromagnetic superexchange, and Jahn-Teller coupling between electrons and phonons. We primarily use a real space Monte Carlo technique to study the phase diagram in terms of applied field $(h)$ and temperature $(T)$, exploring the melting of charge order with increasing $h$ and its recovery on decreasing $h$. We observe hysteresis in this response, and discover that the `field melted' high conductance state can be spatially inhomogeneous even without extrinsic disorder. The hysteretic response plays out in the background of field driven equilibrium phase separation. Our results, exploring $h$, $T$, and the electronic parameter space, are backed up by analysis of simpler limiting cases and a Landau framework for the field response. This paper focuses on our results in the `clean' systems, a companion paper studies the effect of cation disorder on the melting phenomena.