Amplified-reflection plasmon instabilities in grating-gate plasmonic crystals

We theoretically demonstrate that a system formed by two coupled graphene sheets enables a negative damping regime wherein graphene plasmons are pumped by a direct current. This effect is triggered by electrons drifting through one of the graphene sheets and leads to wave instabilities and a spontaneous light emission (spasing) in the midinfrared range. It is shown that there is a deep link between the drift-induced instabilities and wave instabilities in moving media, as both result from the hybridization of oscillators with oppositely signed frequencies. With a thickness of a few nanometers and wide spectral tunability, the proposed structure may find interesting applications in nanophotonic circuitry as an on-chip light source.

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“…[24]. DS-type instabilities were also recently demonstrated in a periodically gated two-dimensional plasmonic crystal under direct current [25].…”

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confidence: 80%

Negative Landau Damping in Bilayer Graphene

Morgado

Silveirinha

2017

Phys. Rev. Lett.

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“…conditions at the junctions of gated and ungated 2DESs include the ballistic current condition [23] and continuity of the potential [24]. These single-point boundary conditions may also be combined with the conditions for the whole junction; an example is the continuity of the plasmon power flow [24].…”

Section: Introductionmentioning

confidence: 99%

Terahertz Plasmon Resonances in Two-Dimensional Electron Systems: Modeling Approaches

et al. 2019

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Known approaches to modeling terahertz plasmons in two-dimensional electron systems may differ significantly in their assumptions. There has, however, been little effort to analyze the differences between and application of different models to the same sets of structures. This paper discusses, develops, and compares several different theoretical approaches-namely, an effective-medium approximation, a transmission-line model, modal analysis, and full-wave simulations. In particular, we present a transmission-line model that takes into account the dielectric-air surrounding a two-dimensional system. Using modal analysis, we also solve analytically the problem of plasmon reflection and transmission when plasmons are incident on a junction between gated and ungated two-dimensional waveguides. Comparing the predictions made by the models for several structures, we find good agreement between full-wave simulations and both analytical and numerical modal analysis. The results of the effective-medium approximation and the transmissionline model also agree with each other, but differ quantitatively from those of the full-wave simulations and modal analysis. We attribute the differences to the phases of the plasmon reflection and transmission coefficients obtained with the different approaches. Our analytical expressions for the plasmon transmission and reflection coefficients represent a simple, yet accurate way to model plasmons in two-dimensional systems comprising both gated and ungated sections.

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“…This makes it difficult to capture a large fraction of the impinging THz beam for the detection or match the device impedance for the emission. Grating gate device structures [11][12][13] could alleviate this second problem and were recently shown to be suitable for the implementation of the DS instability [14]. However, another problem is how to ensure the same gate-to-channel voltages in the field effect transistor channels connected in series [15].…”

Section: Introductionmentioning

confidence: 99%

Current-Driven Dyakonov-Shur Instability in Ballistic Nanostructures with a Stub

2018

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We developed a compact model for the THz plasmonic unstable structures with the tunable narrow channel regions of an increased width (called plasmonic "stubs") using the transmission line analogy and derived the dispersion equations describing unstable plasmons. The solutions of the dispersion equations in the plasmonic systems with the electron drift derived using the hydrodynamic model and generalized to account for the stubs illustrate the device physics and could be used for design and characterization of the THz plasmonic electronic sources. Our results show that adding stubs allows one to control the Dyakonov-Shur instability in plasmonic field effect transistors by optimizing the boundary conditions, controlling the plasma velocity, and making it possible to drive periodic plasmonic structures wirelessly avoiding the contact problems.

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Amplified-reflection plasmon instabilities in grating-gate plasmonic crystals

Cited by 54 publications

References 37 publications

Negative Landau Damping in Bilayer Graphene

Negative Landau Damping in Bilayer Graphene

Terahertz Plasmon Resonances in Two-Dimensional Electron Systems: Modeling Approaches

Current-Driven Dyakonov-Shur Instability in Ballistic Nanostructures with a Stub

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