Anomalous Conductance Oscillations and Half-Metallicity in Atomic Ag-O Chains

TL;DR

This study uses spin density functional theory to explore the electronic and magnetic properties of atomic Ag-O chains, revealing half-metallicity and anomalous conductance oscillations that match experimental observations.

Contribution

It introduces a resonating-chain model that explains conductance oscillations and half-metallicity in atomic silver-oxygen chains, advancing understanding of their electronic behavior.

Findings

Chains longer than 4 atoms become half-metallic with fully spin-polarized carriers.

Conductance oscillates weakly around 0.1G_0, matching experimental data.

The resonating-chain model explains conductance features based on interface reflection and phase-shift.

Abstract

Using spin density functional theory we study the electronic and magnetic properties of atomically thin, suspended chains containing silver and oxygen atoms in an alternating sequence. Chains longer than 4 atoms develop a half-metallic ground state implying fully spin polarized charge carriers. The conductances of the chains exhibit weak even-odd oscillations around an anomalously low value of 0.1G_0 (G_0 = 2e^2h) which coincide with the averaged experimental conductance in the long chain limit. The unusual conductance properties are explained in terms of a resonating-chain model which takes the reflection probability and phase-shift of a single bulk-chain interface as the only input. The model also explains the conductance oscillations for other metallic chains.