Extreme anharmonicity and thermal contraction of 1D wires

TL;DR

This study investigates the thermodynamic and anharmonic properties of ultrathin 1D nanowires, revealing significant negative thermal expansion and deviations from classical heat capacity laws due to strong anharmonic effects.

Contribution

It provides new insights into the anharmonic behaviors and thermal properties of specific 1D nanowires, highlighting their potential for next-generation electronics.

Findings

Colossal negative thermal expansion observed in all studied nanowires.

Large deviations from Dulong-Petit law due to strong anharmonicity.

Exotic thermodynamic features common among 1D wires.

Abstract

Ultrathin nanowires could play a central role in next-generation downscaled electronics. Here, we explore some of the most promising candidates identified from previous high-throughput screening: CuC$_2$, TaSe$_3$, and AuSe$_2$, to gain insight into the thermodynamic and anharmonic behaviors of nanowires that could be exfoliated from weakly-bonded three-dimensional materials. We analyze thermal stability, linear thermal expansion, and anharmonic heat capacity using the stochastic self-consistent harmonic approximation. Notably, our work unveils exotic features common among all the 1D wires: a colossal record negative thermal expansion and very large deviations from the Dulong-Petit law due to strong anharmonicity.