Terahertz magnetoplasmon-polaritons with nonlocal corrections for lossy two dimensional electron gas in GaN-based heterostructures

Abstract

The high electron concentration in GaN-based heterostructures necessitate the consideration of nonlocal corrections in the magnetoconductivity for the study of magnetoplasmon-polaritons (MPPs) in the lossy two dimensional electron gas system with grating couplers. With the complete set of Maxwell equations, the complex dispersion frequency and absorption spectrum are calculated numerically at different magnetic field (B = 10 T) and plasmon wavevectors (k = 5 × 10 m). Taking the AlGaN/GaN structure as a representative case, we observe the cyclotron resonance and its high order harmonics, as well as the MPP modes. The effective aspect ratio of the grating is determined according to the absorption spectrum. Effects of the nonlocal corrections on the dispersion frequency and absorption spectrum are analyzed in detail. The contributions of LO phonons, electron collisions, THz wave polarizations and retardations are also discussed.

Comparative study on calculated terahertz absorption spectra of different heterostructure materials with external magnetic field

“…While at cryogenic temperature, the cyclotron resonance and its high order harmonics were distinguishable from the MPP resonances. It should be mentioned that at specific magnetic field and plasmon wavevector, the MPP modes will probably couple with Bernstein modes and the frequency splitting behavior will appear particularly at cryogenic temperature [14,16]. Similar theoretical and experimental results for the AlGaN/GaN [24,25] and CdMgTe/CdTe [15,19] heterostructure materials have been reported.…”

“…Properties of MPPs in heterostructure materials were evaluated in two different ways. One is the complex dispersion equation established on Maxwell equations and associated boundary conditions between adjacent layers according to the structural and material parameters in each layer [16]. The knowledge of effective filling factor in the periodic grating layer is the precondition to derive the explicit form of complex frequency.…”

“…The local Drude type magnetoconductivity model neglected the effect of the plasmon wavevector selected by the grating period [19]. Moreover, previous simulations results for the AlGaN/GaN material at cryogenic temperature demonstrated that the local model fails in the consideration of the frequency splitting effect of the MPPs mode as well as the high order cyclotron resonance harmonics (CRHs), which possibly appeared as resonance peaks in absorption spectrum at specific values of magnetic field [16]. Therefore, the magnetoconductivity tensor of the 2DEG layer with nonlocal corrections draws a more complete picture, where the MPPs modes, cyclotron resonance and its higher order harmonics are included.…”

Effect of indium doping on motions of 〈a〉-prismatic edge dislocations in wurtzite gallium nitride

“…Due to the unique capacities in tailoring the band gap, GaNbased materials e.g. InGaN and AlGaN, have been extensively used in electronic devices including power electronics, highlyefficient light-emitting optoelectronics, UV detectors, etc [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. However, the performance and lifetime of GaN-based devices have been severely threatened by the presence of high densities of dislocations generated during the crystal growth of GaN [15][16][17][18].…”

Investigation of Phonon Polaritons in an hBN GaN Heterostructure

“…In the wurtzite phase, GaN has lattice constants a = 0.3112 nm and c = 0.4982 nm. There have been increasing evidence of infrared and terahertz polariton activity in GaN systems, particularly in the form of ISB polaritons [53], surface plasmon polaritons [54], [55], magnetoplasmon-polaritons [56], and exciton polaritons [38]. Our studies will use a wurtzite GaN structure, this uniaxial crystal has the dielectric function shown Equation 1.24.…”