Hot electron cooling by acoustic phonons in graphene
| Autor: | Betz, A. C., Vialla, F., Brunel, D., Voisin, C., Picher, M., Cavanna, A., Madouri, A., Fève, G., Berroir, J. -M., Plaçais, B., Pallecchi, E. |
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| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | Phys. Rev. Lett. 109, 056805 (2012) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.109.056805 |
| Popis: | We have investigated the energy loss of hot electrons in metallic graphene by means of GHz noise thermometry at liquid helium temperature. We observe the electronic temperature T / V at low bias in agreement with the heat diffusion to the leads described by the Wiedemann-Franz law. We report on $T\propto\sqrt{V}$ behavior at high bias, which corresponds to a T4 dependence of the cooling power. This is the signature of a 2D acoustic phonon cooling mechanism. From a heat equation analysis of the two regimes we extract accurate values of the electron-acoustic phonon coupling constant $\Sigma$ in monolayer graphene. Our measurements point to an important effect of lattice disorder in the reduction of $\Sigma$, not yet considered by theory. Moreover, our study provides a strong and firm support to the rising field of graphene bolometric detectors. Comment: 5 figures |
| Databáze: | arXiv |
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