Absorption of terahertz radiation by plasmon modes in a grid-gated double-quantum-well field-effect transistor

Abstract

Graphene based field effect transistor for the detection of ammonia J. Appl. Phys. 112, 064304 (2012) Unipolar behavior of asymmetrically doped strained Si0.5Ge0.5 tunneling field-effect transistors Appl. Phys. Lett. 101, 123501 (2012) Efficient physical-thermal model for thermal effects in AlGaN/GaN high electron mobility transistors Appl. Phys. Lett. 101, 122101 (2012) Light/negative bias stress instabilities in indium gallium zinc oxide thin film transistors explained by creation of a double donorThe terahertz absorption spectrum of plasmon modes in a grid-gated double-quantum-well ͑DQW͒ field-effect transistor structure is analyzed theoretically and numerically using a first principles electromagnetic approach and is shown to faithfully reproduce important physical features of recent experimental observations. We find that the essential character of the response-multiple resonances corresponding to spatial harmonics of standing plasmons under the metal grating-is caused by the static spatial modulation of electron density in the channel. Higher order plasmon modes become more optically active as the depth of the electron density modulation in the DQW tends towards unity. The maximum absorbance, at plasma resonance, is shown to be 1/2. Furthermore, the strongest absorption also occurs when the standing plasmon resonance coincides with the fundamental dipole mode of the ungated portion of the channel.

Transmission line theory of collective plasma excitations in periodic two-dimensional electron systems: Finite plasmonic crystals and Tamm states

“…The latter condition is justified if we allow an edge charge accumulation at the boundaries. The edge charge accumulation was confirmed by direct numerical solution of the Maxwell equations in the grating gated 2D electron channel [46]. With these boundary conditions each individual segment of the stepped plasmonic transmission line is represented by the equivalent TL circuit elements defined in Eq.…”

Plasmon enhanced electron drag and terahertz photoconductance in a grating-gated field-effect transistor with two-dimensional electron channel

“…This conclusion was confirmed in Refs. [8,9] where it was shown that the resonant peaks in the photoresponse correlate with plasmon resonances in the channel under the grating gate fingers. In this structure, boundary conditions at the opposite edges of the grating gate fingers are symmetric and can not produce signal rectification.…”

“…At plasmon resonance with wave vector q the Fourier amplitude q E of the total electric field is enhanced in compared with the external THz . The radiative damping is proportional to the equilibrium 2D electron density and also depends on the coupling of the plasmon mode to the EM radiation [8,11]. Dissipative damping is determined by the mobility and increases with the temperature.…”

Усиление терагерцового излучения в плазмонной n-i-p-i-структуре на основе графена с инжекцией носителей заряда

“…Такое поведение связано со сверхизлучательным характером коллективной плазмонной моды. В режиме плазмонного сверхизлучения радиационное затухание растет пропорционально концентрации носителей заря-да, колеблющихся в коллективной плазмонной моде [14], тогда как диссипативное затухание плазмонов равно 1/2τ [15] и не зависит от концентрации носителей заряда в графене. Поскольку концентрация носите-лей заряда в графене связана с энергией Ферми как N n(p) ∝ E 2 F π 2 V 2 F , где V F = 10 8 см/с -скорость Фер-ми, то радиационное затухание растет пропорционально квадрату энергии Ферми.…”