``Flux'' state in double exchange model

TL;DR

This paper investigates the ground state of double-exchange systems, revealing a novel 'flux' state stabilized over other magnetic states, with phase separation occurring at certain doping levels, challenging previous stability assumptions.

Contribution

It introduces the 'flux' state as a new stable ground state in the double exchange model and demonstrates its stability over canted antiferromagnetic states.

Findings

The 'flux' state is stabilized against other magnetic configurations.

Phase separation occurs between 'flux' and antiferromagnetic states.

Canted antiferromagnetic state is not stable in the model.

Abstract

We study the ground state properties of the double-exchange systems. The phase factor of the hopping matrix elements arises from $t_{2g}$ spin texture in two or more dimensions. A novel ``flux'' state is stabilized against the canted antiferromagnetic and spiral spin states. In a certain range of hole doping, the phase separation occurs between the ``flux'' state and antiferromagnetic states. Constructing a trial state which provides the rigorous upper bound on the ground state, we show that the metallic canted antiferromagnetic state is not stable in the double exchange model.