Nonequilibrium thermodynamics of acoustic phonons in suspended graphene
Recent theory has predicted large temperature differences between the in-plane [longitudinal (LA) and transverse (TA)] and out-of-plane [flexural (ZA)] acoustic phonon baths in locally heated suspended graphene. To verify these predictions, and their implications for understanding the nonequilibrium...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2020-03-01
|
| Series: | Physical Review Research |
| Online Access: | http://doi.org/10.1103/PhysRevResearch.2.012058 |
| _version_ | 1797211511352983552 |
|---|---|
| author | Robin J. Dolleman Gerard J. Verbiest Yaroslav M. Blanter Herre S. J. van der Zant Peter G. Steeneken |
| author_facet | Robin J. Dolleman Gerard J. Verbiest Yaroslav M. Blanter Herre S. J. van der Zant Peter G. Steeneken |
| author_sort | Robin J. Dolleman |
| collection | DOAJ |
| description | Recent theory has predicted large temperature differences between the in-plane [longitudinal (LA) and transverse (TA)] and out-of-plane [flexural (ZA)] acoustic phonon baths in locally heated suspended graphene. To verify these predictions, and their implications for understanding the nonequilibrium thermodynamics of two-dimensional (2D) materials, experimental techniques are needed. Here, we present a method to determine the acoustic phonon bath temperatures from the frequency-dependent mechanical response of suspended graphene to a power-modulated laser. The mechanical motion reveals two counteracting contributions to the thermal expansion force, that are attributed to fast positive thermal expansion by the in-plane phonons and slower negative thermal expansion by the out-of-plane phonons. The magnitude of the two forces reveals that the in-plane and flexural acoustic phonons are at very different temperatures in the steady state, with typically observed values of the ratio ΔT_{LA+TA}/ΔT_{ZA} between 0.2 and 3.7. These deviations from the generally used local thermal equilibrium assumption (ΔT_{LA+TA}=ΔT_{ZA}) can affect the experimental analysis of the thermal properties of 2D materials. |
| first_indexed | 2024-04-24T10:27:39Z |
| format | Article |
| id | doaj.art-01889ecffe4e4d388979f2de5726ced3 |
| institution | Directory Open Access Journal |
| issn | 2643-1564 |
| language | English |
| last_indexed | 2024-04-24T10:27:39Z |
| publishDate | 2020-03-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Research |
| spelling | doaj.art-01889ecffe4e4d388979f2de5726ced32024-04-12T16:51:13ZengAmerican Physical SocietyPhysical Review Research2643-15642020-03-012101205810.1103/PhysRevResearch.2.012058Nonequilibrium thermodynamics of acoustic phonons in suspended grapheneRobin J. DollemanGerard J. VerbiestYaroslav M. BlanterHerre S. J. van der ZantPeter G. SteenekenRecent theory has predicted large temperature differences between the in-plane [longitudinal (LA) and transverse (TA)] and out-of-plane [flexural (ZA)] acoustic phonon baths in locally heated suspended graphene. To verify these predictions, and their implications for understanding the nonequilibrium thermodynamics of two-dimensional (2D) materials, experimental techniques are needed. Here, we present a method to determine the acoustic phonon bath temperatures from the frequency-dependent mechanical response of suspended graphene to a power-modulated laser. The mechanical motion reveals two counteracting contributions to the thermal expansion force, that are attributed to fast positive thermal expansion by the in-plane phonons and slower negative thermal expansion by the out-of-plane phonons. The magnitude of the two forces reveals that the in-plane and flexural acoustic phonons are at very different temperatures in the steady state, with typically observed values of the ratio ΔT_{LA+TA}/ΔT_{ZA} between 0.2 and 3.7. These deviations from the generally used local thermal equilibrium assumption (ΔT_{LA+TA}=ΔT_{ZA}) can affect the experimental analysis of the thermal properties of 2D materials.http://doi.org/10.1103/PhysRevResearch.2.012058 |
| spellingShingle | Robin J. Dolleman Gerard J. Verbiest Yaroslav M. Blanter Herre S. J. van der Zant Peter G. Steeneken Nonequilibrium thermodynamics of acoustic phonons in suspended graphene Physical Review Research |
| title | Nonequilibrium thermodynamics of acoustic phonons in suspended graphene |
| title_full | Nonequilibrium thermodynamics of acoustic phonons in suspended graphene |
| title_fullStr | Nonequilibrium thermodynamics of acoustic phonons in suspended graphene |
| title_full_unstemmed | Nonequilibrium thermodynamics of acoustic phonons in suspended graphene |
| title_short | Nonequilibrium thermodynamics of acoustic phonons in suspended graphene |
| title_sort | nonequilibrium thermodynamics of acoustic phonons in suspended graphene |
| url | http://doi.org/10.1103/PhysRevResearch.2.012058 |
| work_keys_str_mv | AT robinjdolleman nonequilibriumthermodynamicsofacousticphononsinsuspendedgraphene AT gerardjverbiest nonequilibriumthermodynamicsofacousticphononsinsuspendedgraphene AT yaroslavmblanter nonequilibriumthermodynamicsofacousticphononsinsuspendedgraphene AT herresjvanderzant nonequilibriumthermodynamicsofacousticphononsinsuspendedgraphene AT petergsteeneken nonequilibriumthermodynamicsofacousticphononsinsuspendedgraphene |