Sponsor
Acknowledgments: Y. X. acknowledges 1) the support from the US National Science Foundation through awards DMR-2317008 and CBET-2445361, 2) the support from the Faculty Development Program at Portland State University, and 3) the computing resources provided by Bridges2 at Pittsburgh Supercomputing Center (PSC) through allocations mat220006p and mat220008p from the Advanced Cyber-infrastructure Coordination Ecosystem: Services & Support (ACCESS) program, which is supported by National Science Foundation grants 2138259, 2138286, 2138307, 2137603, and 2138296.
Published In
Physical Review B
Document Type
Pre-Print
Publication Date
11-10-2025
Subjects
Phonon scatterings
Abstract
igher-order phonon scatterings beyond fourth order remain largely unexplored despite their potential importance in strongly anharmonic materials at elevated temperatures. We develop a theoretical formalism for first-principles calculation of five- and six-phonon scatterings using Green’s function techniques based on a diagrammatic formalism, and systematically investigate multi-phonon interactions in Si, MgO, and BaO from room temperature to near melting points. Our calculations reveal dramatically different material-dependent behaviors: while five- and six-phonon processes remain negligible in Si even at high temperatures, they become increasingly important in MgO near its melting point (3100 K) and in BaO at intermediate temperatures (1200 K). Most remarkably, five- and six-phonon scatterings surpass three- and four-phonon scattering intensity in BaO near its melting point (2100 K), reducing lattice thermal conductivity by over 50%. We demonstrate that the strength of higher-order interactions is primarily governed by interatomic force constants, with BaO exhibiting five- and six-phonon scattering rates over one order of magnitude stronger than MgO despite identical crystal structures, due to large scattering phase space arising from softened harmonic interactions. Our work provides theoretical insights into the lattice dynamics and thermal transport in strongly anharmonic materials and at elevated temperatures.
Rights
© Copyright the author(s) 2025
DOI
10.1103/zxcz-5q9w
Persistent Identifier
https://archives.pdx.edu/ds/psu/44274
Publisher
American Physical Society (APS)
Citation Details
Xia, Y. (2025). First-principles theory of five- and six-phonon scattering. Physical Review B, 112(20).
Description
This is the author’s version of a work that was accepted for publication. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as: First-principles theory of five- and six-phonon scattering. Physical Review B, 112(20).