Cyclotron and plasmon emission from two-dimensional electrons in GaAs

Emission and detection of terahertz radiation using two-dimensional plasmons in semiconductor nanoheterostructures for nondestructive evaluations

“…The 2-D plasmon itself is a nonradiative mode so that a metal-wired grating coupler structure is frequently utilized to yield THz electromagnetic-wave emission. [2][3][4][5][6][7] If the single gate is replaced with a grating-finger-type gate, a plural number of plasmonic cavities (whose electron density is modulated by the bias voltage of the grating-finger gate) are electrostatically coupled (via interfinger region with less electron density) in a spatially distributed configuration. In this case, a constant dc channel current, which is generated by the applied dc drain bias, gives rise to periodic electron velocity modulation over the channel.…”

“…The first is related to thermal excitation of broadband nonresonant plasmons by hot electrons. [2][3][4][5][6][7] The second is related to the plasma wave instability mechanisms like Dyakonov-Shur (DS) Doppler-shift model 8 and/or Ryzhii-Satou-Shur (RSS) transit-time model, 17,18 where coherent plasmons can be excited either by hot electrons or by optical phonon emission under near ballistic electron motion. 31 On the other hand, hydrodynamic nonlinearities of 2-D plasmons in highelectron-mobility transistors (HEMTs) are promising for fast and sensitive rectification/detection of THz radiation.…”

“…It can reach the sub-THz or even THz range for gate lengths of a micron and submicron (nanometer) size. Therefore, different devices/structures of micron and submicron sizes supporting low-dimensional plasmons were intensively studied as possible candidates for solid-state far-infrared (FIR)/THz sources [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] and detectors. [19][20][21][22][23][24][25][26][27][28][29][30] Mechanisms of plasma wave excitation/emission can be divided (by convention) into two types: (1) incoherent and (2) coherent.…”

Emission of terahertz radiation from two-dimensional electron systems in semiconductor nano-heterostructures

“…Two-dimensional (2D) plasmons in semiconductor nano-hetero-structures like electron channels in high-electron mobility transistors (HEMT's) have attracted much attention due to their nature of promoting emission of electromagnetic radiation in the THz range. Therefore different devices/structures of micron and submicron sizes supporting low-dimensional plasmons were intensively studied as possible candidates for solid-state far-infrared (FIR)/THz sources [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Mechanisms of plasma wave excitation/emission can be divided (by convention) into two types: (i) incoherent and (ii) coherent type.…”

“…Mechanisms of plasma wave excitation/emission can be divided (by convention) into two types: (i) incoherent and (ii) coherent type. The first is related to thermal excitation of broadband nonresonant plasmons by hot electrons [2][3][4][5][6][7]. The second is related to the plasma wave instability mechanisms like Dyakonov-Shur Doppler-shift model [8,16] and/or Ryzhii-Satou-Shur transit-time model [17,18], where coherent plasmons can be excited either by hot electrons or by optical phonon emission under near ballistic electron motion [19].…”