Energetics, forces, and quantized conductance in jellium modeled metallic nanowires

TL;DR

This study investigates the energetics, forces, and quantized conductance in jellium-modeled metallic nanowires with variable constrictions, revealing how quantum effects influence mechanical and electrical properties during elongation.

Contribution

It extends previous models to include variable-shaped constrictions, demonstrating the formation of magic configurations and their impact on conductance and force oscillations.

Findings

Energy oscillations correlate with conductance steps.

Quantized transverse states dominate energetics and forces.

Self-selecting stable wire configurations form during elongation.

Abstract

Energetics and quantized conductance in jellium modeled nanowires are investigated using the local density functional based shell correction method, extending our previous study of uniform in shape wires [C. Yannouleas and U. Landman, J. Phys. Chem. B 101, 5780 (1997)] to wires containing a variable shaped constricted region. The energetics of the wire (sodium) as a function of the length of the volume conserving, adiabatically shaped constriction leads to formation of self selecting magic wire configurations. The variations in the energy result in oscillations in the force required to elongate the wire and are directly correlated with the stepwise variations of the conductance of the nanowire in units of 2e^2/h. The oscillatory patterns in the energetics and forces, and the correlated stepwise variation in the conductance are shown, numerically and through a semiclassical analysis, to be dominated by the quantized spectrum of the transverse states at the narrowmost part of the constriction in the wire.