Ultrafast pseudospin dynamics in graphene

Autor:	Trushin, M., Grupp, A., Soavi, G., Budweg, A., De Fazio, D., Sassi, U., Lombardo, A., Ferrari, A. C., Belzig, W., Leitenstorfer, A., Brida, D.
Rok vydání:	2015
Předmět:	Condensed Matter - Mesoscale and Nanoscale Physics
Zdroj:	Phys. Rev. B 92, 165429 (2015)
Druh dokumentu:	Working Paper
DOI:	10.1103/PhysRevB.92.165429
Popis:	Interband optical transitions in graphene are subject to pseudospin selection rules. Impulsive excitation with linearly polarized light generates an anisotropic photocarrier occupation in momentum space that evolves at timescales shorter than 100fs. Here, we investigate the evolution of non-equilibrium charges towards an isotropic distribution by means of fluence-dependent ultrafast spectroscopy and develop an analytical model able to quantify the isotropization process. In contrast to conventional semiconductors, the isotropization is governed by optical phonon emission, rather than electron-electron scattering, which nevertheless contributes in shaping the anisotropic photocarrier occupation within the first few fs. Comment: 9 pages
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1507.08663 Zobrazit plný text záznamu View this record from Arxiv