Direct calculation of modal contributions to thermal conductivity via Green–Kubo modal analysis
We derived a new method for direct calculation of the modal contributions to thermal conductivity, which is termed Green–Kubo modal analysis (GKMA). The GKMA method combines the lattice dynamics formalism with the Green–Kubo formula for thermal conductivity, such that the thermal conductivity become...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2016-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/18/1/013028 |
| _version_ | 1797750795985223680 |
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| author | Wei Lv Asegun Henry |
| author_facet | Wei Lv Asegun Henry |
| author_sort | Wei Lv |
| collection | DOAJ |
| description | We derived a new method for direct calculation of the modal contributions to thermal conductivity, which is termed Green–Kubo modal analysis (GKMA). The GKMA method combines the lattice dynamics formalism with the Green–Kubo formula for thermal conductivity, such that the thermal conductivity becomes a direct summation of modal contributions, where one need not define the phonon velocity. As a result, the GKMA method can be applied to any material/group of atoms, where the atoms vibrate around stable equilibrium positions, which includes non-stoichiometric compounds, random alloys, amorphous materials and even rigid molecules. By using molecular dynamics simulations to obtain the time history of each mode’s contribution to the heat current, one naturally includes anharmonicity to full order and can obtain insight into the interactions between different modes through the cross-correlations. As an example, we applied the GMKA method to crystalline and amorphous silicon. The modal contributions at each frequency result from the analysis and thereby allow one to apply a quantum correction to the mode heat capacity to determine the temperature dependence of thermal conductivity. The predicted temperature dependent thermal conductivity for amorphous silicon shows the best agreement with experiments to date. The GKMA method provides new insight into the nature of phonon transport, as it casts the problem in terms of mode–mode correlation instead of scattering, and provides a general unified formalism that can be used to understand phonon–phonon interactions in essentially any class of materials or structures where the atoms vibrate around stable equilibrium sites. |
| first_indexed | 2024-03-12T16:39:00Z |
| format | Article |
| id | doaj.art-f0d702b6d958463581bad66a918bc6be |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:39:00Z |
| publishDate | 2016-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-f0d702b6d958463581bad66a918bc6be2023-08-08T14:38:25ZengIOP PublishingNew Journal of Physics1367-26302016-01-0118101302810.1088/1367-2630/18/1/013028Direct calculation of modal contributions to thermal conductivity via Green–Kubo modal analysisWei Lv0Asegun Henry1George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USAGeorge W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USAWe derived a new method for direct calculation of the modal contributions to thermal conductivity, which is termed Green–Kubo modal analysis (GKMA). The GKMA method combines the lattice dynamics formalism with the Green–Kubo formula for thermal conductivity, such that the thermal conductivity becomes a direct summation of modal contributions, where one need not define the phonon velocity. As a result, the GKMA method can be applied to any material/group of atoms, where the atoms vibrate around stable equilibrium positions, which includes non-stoichiometric compounds, random alloys, amorphous materials and even rigid molecules. By using molecular dynamics simulations to obtain the time history of each mode’s contribution to the heat current, one naturally includes anharmonicity to full order and can obtain insight into the interactions between different modes through the cross-correlations. As an example, we applied the GMKA method to crystalline and amorphous silicon. The modal contributions at each frequency result from the analysis and thereby allow one to apply a quantum correction to the mode heat capacity to determine the temperature dependence of thermal conductivity. The predicted temperature dependent thermal conductivity for amorphous silicon shows the best agreement with experiments to date. The GKMA method provides new insight into the nature of phonon transport, as it casts the problem in terms of mode–mode correlation instead of scattering, and provides a general unified formalism that can be used to understand phonon–phonon interactions in essentially any class of materials or structures where the atoms vibrate around stable equilibrium sites.https://doi.org/10.1088/1367-2630/18/1/013028amorphous materialsmolecular dynamicsnanoscale heat transferspectral thermal conductivitylattice dynamics |
| spellingShingle | Wei Lv Asegun Henry Direct calculation of modal contributions to thermal conductivity via Green–Kubo modal analysis New Journal of Physics amorphous materials molecular dynamics nanoscale heat transfer spectral thermal conductivity lattice dynamics |
| title | Direct calculation of modal contributions to thermal conductivity via Green–Kubo modal analysis |
| title_full | Direct calculation of modal contributions to thermal conductivity via Green–Kubo modal analysis |
| title_fullStr | Direct calculation of modal contributions to thermal conductivity via Green–Kubo modal analysis |
| title_full_unstemmed | Direct calculation of modal contributions to thermal conductivity via Green–Kubo modal analysis |
| title_short | Direct calculation of modal contributions to thermal conductivity via Green–Kubo modal analysis |
| title_sort | direct calculation of modal contributions to thermal conductivity via green kubo modal analysis |
| topic | amorphous materials molecular dynamics nanoscale heat transfer spectral thermal conductivity lattice dynamics |
| url | https://doi.org/10.1088/1367-2630/18/1/013028 |
| work_keys_str_mv | AT weilv directcalculationofmodalcontributionstothermalconductivityviagreenkubomodalanalysis AT asegunhenry directcalculationofmodalcontributionstothermalconductivityviagreenkubomodalanalysis |