Work

Observation of coherently modulated thermal phonon band and lifetime in superlattice

Year: 2026

Type: preprint

Abstract: Manipulating phonon band structures through wave interference in artificial periodic nanostructures is of fundamental interest and forms the foundation of phonon band engineering. Yet, direct observation of thermal phonon wave interference has remained elusive despite half a century of extensive research. Here, utilizing inelastic x-ray scattering, we directly observed momentum-resolved coherently modulated thermal phonon bands and lifetimes in a short-period GaAs/AlAs superlattice at 300 K. The modulation persists at even 500 K, demonstrating robust coherent thermal phonon transport at high temperatures. Our measurements, combined with ab initio lattice-dynamics calculations, further show that thermal phonon interference expands the three-phonon scattering phase space and strengthens anharmonic effects, highlighting the interplay between phonon band modulation and anharmonicity. Our observations establish nanostructuring as a versatile route for engineering thermal phonon bands and lifetimes at high temperatures across diverse applications.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2606.11696

Authors: Liao, Yuxuan, Uchiyama, Hiroshi, Nagai, Naomi, Morais, Natalia, Manjo, Taiushun, Guo, Rulei, Chandra, Harsh, Nagahiro, Ryohei, Xu, Bin, Fukui, Hiroshi, Ishikawa, Daisuke, Baron, Alfred Q. R., Arakawa, Yasuhiko, Hirakawa, Kazuhiko, Shiomi, Junichiro

Institutions: Bunkyo University, The University of Tokyo, Japan Synchrotron Radiation Research Institute, Institute of Industrial Science, The University of Tokyo, Institute for Nano Quantum Information Electronics, The University of Tokyo, SPring-8

Language: English

Topic: Thermal properties of materials

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: Japan Society for the Promotion of Science, Japan Science and Technology Agency, Institute for Materials Research, Tohoku University, Division of Materials Research, Core Research for Evolutional Science and Technology

Awards: Meta-phononics of disordered solid system including mass transport, Ultimate Suppression of Nanoscale Heat Transport with Quasi-phononic Crystal, Achieving thermal conductivity reduction of phononic crystals through deepening the transport theory of phonon waves, G4995607337, Terahertz dynamics of single molecule transistors and its application to quantum information processing, 巨大連続空間探索による不秩序熱機能材料の革新

OpenAlex ID: W7164401624

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