Ground-state properties of a Peierls-Hubbard triangular prism

TL;DR

This paper models a platinum-halide triangular prism using a Peierls-Hubbard Hamiltonian, revealing complex valence states and phase transitions, including novel insulator-metal and insulator-insulator transitions driven by doping.

Contribution

It introduces a group-theoretical approach to characterize valence arrangements and phase transitions in a Peierls-Hubbard model of a nanotube-based transition-metal complex.

Findings

Identification of heterogeneous and metallic charge-density-wave states.

Observation of first-order insulator-to-metal transitions under doping.

Detection of second-order insulator-to-insulator transitions.

Abstract

Motivated by recent chemical attempts at assembling halogen-bridged transition-metal complexes within a nanotube, we model and characterize a platinum-halide triangular prism in terms of a Peierls-Hubbard Hamiltonian. Based on a group-theoretical argument, we reveal a variety of valence arrangements, including heterogeneous or partially metallic charge-density-wave states. Quantum and thermal phase competitions are numerically demonstrated with particular emphasis on novel insulator-to-metal and insulator-to-insulator transitions under doping, the former of which is of the first order, while the latter of which is of the second order.