High-Order Anharmonicities Shape Phonon Hydrodynamic Effects in Graphene
Tur Prats, Jordi (Universitat Autònoma de Barcelona. Departament de Física)
Han, Zherui (Purdue University. Birck Nanotechnology Center)
Beardo Ricol, Albert (Universitat Autònoma de Barcelona. Departament de Física)
Ruan, Xiulin (Purdue University. Birck Nanotechnology Center)
Àlvarez Calafell, Francesc Xavier (Universitat Autònoma de Barcelona. Departament de Física)

Data:	2025
Resum:	Prominent phonon hydrodynamic phenomena were predicted in graphene at low temperatures due to the abundance of momentum-conserving three-phonon interactions. Recent studies, however, have shown that higher-order interactions constitute an additional resistive channel that significantly reduces the thermal conductivity of this material. Here, we show that the occurrence of hydrodynamic effects in graphene is severely conditioned by four-phonon interactions. Contrary to conventional understanding, we first demonstrate that the collective limit assumption, in which the phonon distribution is fully correlated, is not adequate to understand the hydrodynamic transport mechanisms in graphene. Then we report the key hydrodynamic parameters, namely the nonlocal length and the heat flux relaxation time, and we show that they are significantly reduced if considering full anharmonicity. Finally, we discuss observable implications in a variety of experimental configurations and we critically review previous predictions on the necessary conditions for the manifestation of collective phonon behavior and phonon hydrodynamics.
Ajuts:	Agencia Estatal de Investigación PID2021-122322NB-I00 Agencia Estatal de Investigación TED2021-129612B-C22 Agència de Gestió d'Ajuts Universitaris i de Recerca 2021/SGR-00644
Nota:	Altres ajuts: acords transformatius de la UAB
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Graphene ; Phonon hydrodynamics ; Four-phonon interactions ; Second sound ; Phonon viscosity
Publicat a:	Nano letters, (July 2025) , ISSN 1530-6992

DOI: 10.1021/acs.nanolett.5c00855
PMID: 40635367

7 p, 2.7 MB

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