Open AccessУсиление терагерцовых электромагнитных волн в структуре с двумя слоями графена при протекании постоянного электрического тока: гидродинамическое приближение
Author(s) -
И.М. Моисеенко,
В.В Попов,
Д.В. Фатеев
Publication year - 2021
Publication title -
fizika i tehnika poluprovodnikov
Language(s) - English
Resource type - Journals
eISSN - 1726-7315
pISSN - 0015-3222
DOI - 10.21883/ftp.2021.08.51130.06
Subject(s) - graphene , terahertz radiation , materials science , electromagnetic radiation , conductivity , dispersion (optics) , charge carrier , current (fluid) , phase (matter) , electrical resistivity and conductivity , optoelectronics , electric current , optics , physics , nanotechnology , quantum mechanics , thermodynamics
The amplification of electromagnetic terahertz radiation in a structure with two layers of hydrodynamic graphene with a direct electric current is studied theoretically. The hydrodynamic conductivity of graphene is investigated. It is shown that the real part of the graphene conductivity can be negative in the terahertz frequency range at the drift velocities of charge carriers in graphene that are lower than the phase velocity of the electromagnetic wave. For small wavevectors of a terahertz wave incident on a graphene structure, the spatial dispersion insignificantly contributes to the hydrodynamic graphene conductivity. Because of this, the amplification efficiency does not depend on the direction of currents in each of the graphene layers. It is shown that graphene with direct electric current can be used to create THz amplifiers operating at room temperature.