Classical Disordered Ground States: Super-Ideal Gases, and Stealth and Equi-Luminous Materials

TL;DR

This paper constructs disordered ground-state configurations of particle systems with specific radiation scattering properties, revealing new classes of materials like stealth, super-ideal, and equi-luminous materials, with implications for material design.

Contribution

It introduces a collective coordinate optimization method to create disordered ground states with tailored scattering characteristics, including stealth, super-ideal, and equi-luminous materials.

Findings

Ground states can be disordered in the infinite-volume limit.

Configurations tend to form clusters as prescribed luminosity increases.

The method enables design of materials with specific scattering properties.

Abstract

Using a collective coordinate numerical optimization procedure, we construct ground-state configurations of interacting particle systems in various space dimensions so that the scattering of radiation exactly matches a prescribed pattern for a set of wave vectors. We show that the constructed ground states are, counterintuitively, disordered (i.e., possess no long-range order) in the infinite-volume limit. We focus on three classes of configurations with unique radiation scattering characteristics: (i)``stealth'' materials, which are transparent to incident radiation at certain wavelengths; (ii)``super-ideal'' gases, which scatter radiation identically to that of an ensemble of ideal gas configurations for a selected set of wave vectors; and (iii)``equi-luminous'' materials, which scatter radiation equally intensely for a selected set of wave vectors. We find that ground-state configurations have an increased tendency to contain clusters of particles as one increases the prescribed luminosity. Limitations and consequences of this procedure are detailed.