Terahertz negative dynamic conductivity in optically pumped graphene

A. Satou, T. Otsuji, V. Ryzhii, F. T. Vasko

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We theoretically study the carrier relaxation dynamics in intrinsic graphene under pulse excitation taking into account optical-phonon (OP) scattering and carrier-carrier (CC) scattering. We consider the two limiting cases (a) where the CC scattering quasi-equilibrates carriers at all times, and (b) where the energy relaxation by intraband OP emission is dominant. We develop rate equations for the quasi-Fermi level and carrier temperature and calculate their time evolution. It is shown that in both cases the population inversion in the terahertz (THz) range can be achieved on the order of 10 ps after the pulse excitation. It is revealed that the threshold pumping intensity for the population inversion and negative dynamic conductivity in the case (a) is one order of magnitude smaller than that in the case (b) because of the thermal broadening of the carrier distribution by the CC scattering.

Original languageEnglish
Title of host publicationPIERS 2012 Kuala Lumpur - Progress in Electromagnetics Research Symposium, Proceedings
Number of pages5
Publication statusPublished - 2012 Nov 12
EventProgress in Electromagnetics Research Symposium, PIERS 2012 Kuala Lumpur - Kuala Lumpur, Malaysia
Duration: 2012 Mar 272012 Mar 30

Publication series

NameProgress in Electromagnetics Research Symposium
ISSN (Print)1559-9450


OtherProgress in Electromagnetics Research Symposium, PIERS 2012 Kuala Lumpur
CityKuala Lumpur

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials


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