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Interpretation of apparent thermal conductivity in finite systems from equilibrium molecular dynamics simulations

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journal contribution
posted on 22.03.2021, 12:25 by Haikuan Dong, Shiyun Xiong, Zheyong Fan, Ping Qian, Yanjing Su, Tapio Ala-NissilaTapio Ala-Nissila
We propose a way to properly interpret the apparent thermal conductivity obtained for finite systems using equilibrium molecular dynamics simulations (EMD) with fixed or open boundary conditions in the transport direction. In such systems the heat current autocorrelation function develops negative values after a correlation time which is proportional to the length of the simulation cell in the transport direction. Accordingly, the running thermal conductivity develops a maximum value at the same correlation time and eventually decays to zero. By comparing EMD with nonequilibrium molecular dynamics (NEMD) simulations, we conclude that the maximum thermal conductivity from EMD in a system with domain length 2L is equal to the thermal conductivity from NEMD in a system with domain length L. This facilitates the use of nonperiodic-boundary EMD for thermal transport in finite samples in close correspondence to NEMD.

Funding

National Key Research and Development Program of China under Grants No. 2016YFB0700500 and No. 2018YFB0704300

National Natural Science Foundation of China under Grants No. 11974059 and No. 11804242

Science Foundation from Education Department of Liaoning Province under Grant No. LQ2020008

Academy of Finland through its QTF Centre of Excellence Programme under Project No. 312298

History

School

  • Science

Department

  • Mathematical Sciences

Published in

Physical Review B

Volume

103

Issue

3

Publisher

American Physical Society (APS)

Version

AM (Accepted Manuscript)

Rights holder

© American Physical Society

Publisher statement

This paper was accepted for publication in the journal Physical Review B and the definitive published version is available at https://doi.org/10.1103/PhysRevB.103.035417.

Acceptance date

05/01/2021

Publication date

2021-01-19

Copyright date

2021

ISSN

2469-9950

eISSN

2469-9969

Language

en

Depositor

Prof Tapio Ala-Nissila. Deposit date: 18 March 2021

Article number

035417