Negative conductivity of graphene with direct electric current

2021 ◽  
Author(s):  
I.M. Moiseenko ◽  
V.V. Popov ◽  
D.V. Fateev
Keyword(s):  
Reflection Coefficient ◽  
Electric Current ◽  
Terahertz Radiation ◽  
Room Temperature ◽  
Negative Real Part ◽  
Wave Incident ◽  
Thz Radiation ◽  
Direct Electric Current ◽  
Radiation Sources ◽  
Dc Current

Problem formulating. Currently, there are no compact, efficient terahertz radiation sources operating at room temperature. To create such sources and amplifiers, structures based on graphene with DC-current can be used. Goal. Finding conditions for achieving the negative real part of graphene conductivity and amplification of THz radiation in graphene with a direct electric current. Result. It is shown that for a certain value of direct electric current in graphene, the reflection coefficient of the THz wave incident on the structure based on graphene with DC-current exceeds unity, which indicates the amplification of THz radiation in the structure. The amplification of the THz radiation in graphene is achieved due to negative values of the real part of the graphene conductivity. Practical meaning. Results can be used to create sources and amplifiers of terahertz radiation.

scholarly journals Photothermal, Photoelectric, and Photothermoelectric Effects in Bi-Sb Thin Films in the Terahertz Frequency Range at Room Temperature

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 76
Author(s):  
Mikhail K. Khodzitsky ◽  
Petr S. Demchenko ◽  
Dmitry V. Zykov ◽  
Anton D. Zaitsev ◽  
Elena S. Makarova ◽  
...  
Keyword(s):  
Thin Films ◽  
Terahertz Radiation ◽  
Room Temperature ◽  
Voltage Drop ◽  
Radiation Detection ◽  
Radiation Detectors ◽  
Thz Radiation ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Frequency Range

The terahertz frequency range is promising for solving various practically important problems. However, for the terahertz technology development, there is still a problem with the lack of affordable and effective terahertz devices. One of the main tasks is to search for new materials with high sensitivity to terahertz radiation at room temperature. Bi1−xSbx thin films with various Sb concentrations seem to be suitable for such conditions. In this paper, the terahertz radiation influence onto the properties of thermoelectric Bi1−xSbx 200 nm films was investigated for the first time. The films were obtained by means of thermal evaporation in vacuum. They were affected by terahertz radiation at the frequency of 0.14 terahertz (THz) in the presence of thermal gradient, electric field or without these influences. The temporal dependencies of photoconductivity, temperature difference and voltage drop were measured. The obtained data demonstrate the possibility for practical use of Bi1−xSbx thin films for THz radiation detection. The results of our work promote the usage of these thermoelectric materials, as well as THz radiation detectors based on them, in various areas of modern THz photonics.

scholarly journals Усиление терагерцовых электромагнитных волн в структуре с двумя слоями графена при протекании постоянного электрического тока: гидродинамическое приближение

2021 ◽  
Vol 55 (8) ◽  
pp. 649
Author(s):  
И.М. Моисеенко ◽  
В.В Попов ◽  
Д.В. Фатеев
Keyword(s):  
Electric Current ◽  
Room Temperature ◽  
Spatial Dispersion ◽  
Terahertz Wave ◽  
Charge Carriers ◽  
Amplification Efficiency ◽  
Terahertz Frequency ◽  
Terahertz Frequency Range ◽  
Direct Electric Current ◽  
Graphene Layers

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.

scholarly journals Progress in Compact Room Temperature THz Radiation Sources

2012 ◽  
Vol 2 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Ross Leyman ◽  
Natalia Bazieva ◽  
Tomasz Kruczek ◽  
Grigorii S. Sokolovskii ◽  
Edik U. Rafailov
Keyword(s):  
Room Temperature ◽  
Thz Radiation ◽  
Radiation Sources

scholarly journals Progress in Compact Room Temperature THz Radiation Sources

2012 ◽  
Vol 2 (1) ◽  
pp. 12-22 ◽  
Author(s):  
Ross Leyman ◽  
Natalia Bazieva ◽  
Tomasz Kruczek ◽  
Grigorii S. Sokolovskii ◽  
Edik U. Rafailov
Keyword(s):  
Room Temperature ◽  
Thz Radiation ◽  
Radiation Sources

The Isotope Effect of a Direct Electric Current through Liquid and Solid Metals

1956 ◽  
Vol 11 (1) ◽  
pp. 71-75
Author(s):  
E. Haeffner ◽  
Th. Sjöborg ◽  
S. Lindhe
Keyword(s):  
Liquid Metal ◽  
Electric Current ◽  
Isotope Effect ◽  
Direct Current ◽  
Capillary Tube ◽  
Isotope Separation ◽  
Direct Electric Current ◽  
Separation Effect ◽  
A Current

The isotope separation effect of a direct electric current in a liquid metal is demonstrated by passing a current through mercury, which is enclosed in a capillary tube. The second part of the paper deals with an attempt of establishing an isotope effect when a direct current is passed through an uranium wire.

Antimicrobial Efficacy of Exposure of Medical Metal Implants to Direct Electric Current

2022 ◽  
Author(s):  
E. N. Ovchinnikov ◽  
N. V. Godovykh ◽  
O. V. Dyuryagina ◽  
M. V. Stogov ◽  
D. N. Ovchinnikov ◽  
...  
Keyword(s):  
Electric Current ◽  
Antimicrobial Efficacy ◽  
Direct Electric Current ◽  
Metal Implants
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