Novel insights into charge and spin pairing instabilities in nanoclusters

TL;DR

This paper investigates charge and spin pairing instabilities in nanoclusters, revealing how interaction strength, doping, and temperature influence phase behavior, with implications for understanding nanoscale phenomena in complex materials.

Contribution

It provides exact calculations of collective excitations and phase diagrams in nanoclusters, offering new insights into charge-spin interactions and phase separation mechanisms.

Findings

Charge and spin collective excitations depend on interaction parameters.

Phase diagrams show inhomogeneous nanoscale phases similar to high T_c cuprates.

Criteria for spin-charge separation are established.

Abstract

Electron pairing and ferromagnetism in various cluster geometries are studied with emphasis on tetrahedron and square pyramid under variation of interaction strength, electron doping and temperature. These exact calculations of charge and spin collective excitations and pseudogaps yield intriguing insights into level crossing degeneracies, phase separation and condensation. Criteria for spin-charge separation and reconciliation driven by interaction strength, next nearest coupling and temperature are found. Phase diagrams resemble a number of inhomogeneous, coherent and incoherent nanoscale phases seen recently in high T$_c$ cuprates, manganites and CMR nanomaterials.