The Instability of Terahertz Plasma Waves in Two Dimensional Gated and Ungated Quantum Electron Gas

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In this paper, the Dyakonov-Shur instability of terahertz (THz) plasma waves has been analyzed in gated cylindrical field effect transistor (FET). In the cylindrical FET, the hydrodynamic equations in cylindrical coordinates are used to describe the THz plasma wave in twodimensional electronic gas. The research results show that the oscillation frequency of the THz plasma wave is increased by increasing the component of wave in the circumferential direction, but instability increment of the THz plasma wave are increased by increasing the radius of channel.

“…where the K 1 and K 2 can be found from equation (10). Equation ( 14) is a transcendental equation that can be only solved numerically.…”

Section: Plasma Waves Instabilitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The instability of terahertz plasma waves in cylindrical FET

Zhang

2019

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“…we obtain 15 This is greater than one, meaning that the amplitude of plasma in an NDC HEMT with the same condition is more than in an ordinary transistor. For a numerical example we use the estimation of references [4,15] as a typical value for  h » » m 0.0018. As an example we consider the data in [1] as For a gate to source DC bias of j = 1 2 0 V, we obtain A HEMT =0.3074, A NDC =0.3974.…”

Section: Dyakonov-shur Instabilitymentioning

confidence: 99%

“…In [15] the gated and ungated region of a two-dimensional quantum electron gas (2DQEG) has been investigated, showing that the radiation frequency and the instability in an ungated 2DQEG are much higher than that in a gated 2DQEG. The quantum effects always enhance the instability and finally he concluded that both gated and ungated parts take part in that process of emission and detection.…”

Section: Introductionmentioning

confidence: 99%

Two-dimensional analysis of a negative differential conductance gate transistor as a THz emitter

Rahmatallahpur

Rostami

Khorram

2017

We investigate plasma modes in a transistor including a negative differential conductance in the gate. The analytical results show that the plasma wave generation is substantially influenced by the lateral direction (width of the transistor), gate leakage current and viscosity. The injection from the gate (opposed to the gate leakage current) can improve the plasma oscillations and their amplitude with respect to ordinary transistors. We also estimate, which to our best knowledge has been derived for the first time, the total power emitted by the transistor and the emitted pattern which qualitatively gives reasonable agreement with the experimental data. The results show that the radiated power depends on various parameters such as drift velocity, momentum relaxation time, gate leakage current and especially the lateral direction. A negative gate current enhances the power while the gate leakage current decreases the power.

“…Furthermore, the plasma wave is similar to 'shallow water' waves in a ballistic FET. It is indicated that the instability with zero ac voltage at the source and zero ac current at the drain can occurs when the asymmetric boundary conditions are satisfied [2,3]. Most of the previous work demonstrated the THz plasma wave instability in short-channel FET is essential to the realization of practical non-resonant detectors [4][5][6], resonant detectors [7], and the terahertz emitters [8] in the terahertz domain [4].…”

Section: Introductionmentioning

confidence: 99%

THz plasma wave instability in field effect transistor with electron diffusion current density

Zhang

2018

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The plasma wave instability in rectangle field effect transistors (FETs) is studied with electron diffusion current density by quantum hydrodynamic model in this paper. General dispersion relation including effects of electrical thermal motion, external friction associated with electron scattering effect, electron exchange-correlation contributions and quantum effects were obtained for rectangle FETs. The electron diffusion current density term is considered for further analysis in this paper. It is found that the quantum effects, the electron diffusion current density and electrical thermal motion enhance the radiation power and frequencies. But the electron exchangecorrelation effects and the electron scattering effects reduce the radiation power and frequencies. Results showed that a transistor has advantages for the realization of practical terahertz sources.