Relaxation of charge in monolayer graphene: fast non-linear diffusion vs Coulomb effects
| Autor: | Kolomeisky, Eugene B., Straley, Joseph P. |
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| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 95, 045415 (2017) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.95.045415 |
| Popis: | Pristine monolayer graphene exhibits very poor screening because the density of states vanishes at the Dirac point. As a result, charge relaxation is controlled by the effects of zero-point motion (rather than by the Coulomb interaction) over a wide range of parameters. Combined with the fact that graphene possesses finite intrinsic conductivity, this leads to a regime of relaxation described by a non-linear diffusion equation with a diffusion coefficient that diverges at zero charge density. Some consequences of this fast diffusion are self-similar superdiffusive regimes of relaxation, the development of a charge depleted region at the interface between electron- and hole-rich regions, and finite extinction times for periodic charge profiles. Comment: 5 pages, minor changes, version to be published in Phys. Rev. B |
| Databáze: | arXiv |
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