Collective rotations in oxides

TL;DR

This paper introduces a Hamiltonian model to describe collective oxygen atom rotations in oxides, analyzing phase diagrams and excitations, with applications to silica and copper oxides.

Contribution

It presents a new Hamiltonian framework for understanding collective oxygen rotations and characterizes phase transitions and excitations in oxides.

Findings

Identified phases with non-phononic excitations.

Estimated material parameters for silica and Cu oxides.

Mapped zero-temperature phase diagrams.

Abstract

Based on bond arguments, a Hamiltonian is introduced to describe the fundamental physics of the collective rotations of oxygen atoms in oxides. Values for the relevant material parameters are estimated for silica and Cu oxides. Zero-temperature phase diagrams are presented; the different phases and associated transitions are characterized. Phases with non-phononic excitations are found.