An international collaborative research team successfully generated an ultrauniform (hyperuniform) disordered solid known as hyperuniform glass, which exhibits exceptional stability. The research team included Senior Program Advisor (Professor Emeritus) Hajime Tanaka and Project Researcher Yinqiao Wang from the Research Center for Advanced Science and Technology, the University of Tokyo, as well as Graduate Student Zhuang Qian and Professor Hua Tong from the University of Science and Technology of China. They also clarified the fundamental properties of this material and made new discoveries related to jamming transition and ideal glass transition. The results were published in Nature Communications.
Snapshots of (a) the initial randomly packed state and (b) the hyperuniform overpacked glassy state after iterative processing using a new algorithm. Particles are color-coded based on the local packing fraction ϕi = 4πRi3 / 3Vi, where Ri is the particle radius and Vi is the corresponding Voronoi volume.
(c) Density spectrum χv(q) at different iteration numbers. As the number of iterations increases, density fluctuations in the low-wavenumber region decrease, eventually achieving the power-law scaling indicated by the dashed line.
Provided by the University of Tokyo
Hyperuniform glass is characterized by considerably suppressed density fluctuations in the low wavenumber (q) range, meaning it maintains uniform density at large length scales. This distinctive property sets it apart as a unique glass state. In the study of jamming transition, where particles change from fluid-like to solid-like behavior as they become more densely packed, researchers have long debated the hyperuniformity characteristics just above the jamming transition point and whether hyperuniformity is preserved in higher-density states above the aforementioned point.
For the first time, the research team numerically generated a disordered solid with the highest hyperuniformity in high-density states that are far beyond the jamming point. They created this solid using a specialized algorithm. This glass state follows a power law density spectrum (qα) with α = 4.
Additionally, by depressurizing hyperuniform over-jammed states and typical over-jammed states with significant density fluctuations down to their respective jamming points, they confirmed the existence of a protocol-independent power law exponent in the hyperuniform state just above the jamming transition point.
Specifically, the group found that the density hyperuniformity exponent was approximately α ≈ 0.25, while the hyperuniformity exponent for the number of interparticle contacts was approximately α ≈ 2. Both values were deeply connected to the critical properties of the jamming transition point. Furthermore, while the marginally jammed state and conventional over-jammed state exhibited marginal stability, the hyperuniform over-jammed state demonstrated exceptional vibrational, dynamic, thermodynamic, and mechanical stabilities, comparable to those of crystals.
These findings demonstrate that the hyperuniform over-jammed state provides valuable clues for the ideal disordered solid state and are expected to substantially impact the design of novel glass states with hyperuniformity and hyperstability. They may also contribute to the development of metamaterials with disordered structures for practical applications.
Tanaka stated, "More than 20 years ago, Torquato and Stillinger proposed the concept of 'disordered hyperuniformity,' where density fluctuations at long wavelengths are suppressed in densely packed disordered states. Disordered hyperuniform materials combine the isotropy of liquids with the suppression of density fluctuations seen in crystals, resulting in excellent optical and electronic properties. We successfully generated a thermodynamically and mechanically stable hyperuniform over-jammed glass state, proving that glass can achieve a stability level comparable to crystals. We hope that our results will improve stability and facilitate new applications for glass materials."
Journal Information
Publication: Nature Communications
Title: Hyperuniform disordered solids with crystal-like stability
DOI: 10.1038/s41467-025-56283-1
This article has been translated by JST with permission from The Science News Ltd. (https://sci-news.co.jp/). Unauthorized reproduction of the article and photographs is prohibited.