Impact of disorder on Dirac plasmon losses

Principi, Alessandro; Vignale, Giovanni; Carrega, Matteo; Polini, Marco

doi:10.1103/physrevb.88.121405

Cited by 58 publications

(91 citation statements)

References 28 publications

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“…By comparing our data with the calculated inverse damping ratios, we find that impurity scattering does not play a role for plasmon damping in these high-quality heterostructures, because it would lead to strongly reduced damping for increasing n s , owing to increasing electrostatic screening 37 . This trend is shown by the green dash-dotted curve in Fig.…”

mentioning

confidence: 86%

“…This trend is shown by the green dash-dotted curve in Fig. 4 which is based on a plasmon damping theory due to impurity scattering 37 . In contrast, plasmon damping by intrinsic thermal phonons 32 shows a much weaker dependence on n s (dashed blue curve in Fig.…”

mentioning

confidence: 92%

“…The calculations are based on the nonlocal conductivity σ (q, ω) evaluated at a plasmon wavevector q = q p and excitation frequency ω. These calculations show that charge carrier scattering is strongly modified at high frequency and thus the effective electron scattering time for plasmons can differ from the transport scattering time 32,37 .…”

mentioning

confidence: 95%

“…Coherent many-electron scattering processes have been calculated to play a minor role 38 . Besides dissipating energy electronically, plasmons also dissipate via dielectric losses in the environment, for example, through direct heating of the substrate 32,37 .…”

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confidence: 99%

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Highly confined low-loss plasmons in graphene–boron nitride heterostructures

et al. 2014

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Graphene plasmons were predicted to possess simultaneous ultrastrong field confinement and very low damping, enabling new classes of devices for deep-subwavelength metamaterials, single-photon nonlinearities, extraordinarily strong light-matter interactions and nano-optoelectronic switches. Although all of these great prospects require low damping, thus far strong plasmon damping has been observed, with both impurity scattering and many-body effects in graphene proposed as possible explanations. With the advent of van der Waals heterostructures, new methods have been developed to integrate graphene with other atomically flat materials. In this Article we exploit near-field microscopy to image propagating plasmons in high-quality graphene encapsulated between two films of hexagonal boron nitride (h-BN). We determine the dispersion and plasmon damping in real space. We find unprecedentedly low plasmon damping combined with strong field confinement and confirm the high uniformity of this plasmonic medium. The main damping channels are attributed to intrinsic thermal phonons in the graphene and dielectric losses in the h-BN. The observation and in-depth understanding of low plasmon damping is the key to the development of graphene nanophotonic and nano-optoelectronic devices.

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confidence: 86%

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confidence: 92%

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confidence: 95%

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confidence: 99%

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Highly confined low-loss plasmons in graphene–boron nitride heterostructures

et al. 2014

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“…4(a)]. The origin for the higher γ TBLG p at smaller θ in the Dirac regime (θ ≥ 3°) is likely due to the stronger charge scattering rates [49,50]. According to previous literature [51], the charge scattering rates (Γ) due to either long-range Coulomb scattering or short-range defect scattering are inverse proportional to the Fermi velocity.…”

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confidence: 83%

Real-Space Imaging of the Tailored Plasmons in Twisted Bilayer Graphene

Das

Luan

et al. 2017

Phys. Rev. Lett.

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We report a systematic plasmonic study of twisted bilayer graphene (TBLG)two graphene layers stacked with a twist angle. Through real-space nanoimaging of TBLG single crystals with a wide distribution of twist angles, we find that TBLG supports confined infrared plasmons that are sensitively dependent on the twist angle. At small twist angles, TBLG has a plasmon wavelength comparable to that of single-layer graphene (SLG). At larger twist angles, the plasmon wavelength of TBLG increases significantly with apparently lower damping. Further analysis and modeling indicate that the observed twist-angle-dependence of TBLG plasmons in the Dirac linear regime is mainly due to the Fermi-velocity renormalization, a direct consequence of interlayer electronic coupling. Our work unveils the tailored plasmonic characteristics of TBLG and deepens our understanding of the intriguing nano-optical physics in novel van der Waals (vdW) coupled two-dimensional (2D) materials. Main textGraphene Dirac plasmons [1-6], which are collective oscillations of Dirac fermions in graphene, have been widely investigated in recent years by using both the electron energy loss spectroscopy [7-9] and optical imaging/spectroscopy [10][11][12][13][14][15][16][17][18][19][20][21] techniques. These quasiparticles demonstrate many superior characteristics including high confinement, long lifetime, strong field enhancement, broad spectral range, electrical tunability and a broad spectral range from terahertz to infrared .

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A Multibeam Interference Model for Analyzing Complex Near‐Field Images of Polaritons in 2D van der Waals Microstructures

Liao

Guo

et al. 2019

Adv Funct Materials

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Van der Waals (vdW) materials are among the most promising candidates for photonic integrated circuits because they support a full set of polaritons that can manipulate light at deep subdiffraction nanoscale. It is possible to directly probe the propagating polaritons in vdW materials in real space via scattering-type scanning near-field optical microscopy, such that the wave vector and lifetime of the polaritons can be extracted from as-measured interference fringes by Fourier analysis. However, this method is unsuitable for clutter interference patterns in samples exhibiting inadequate fringes due to small size (less than 10 µm) or complex edges that are often encountered in nanophotonic devices and new material characterization. Here, a multibeam interference model is developed to analyze complex images by disentangling them into periodic patterns and residue. By employing phase stationary approximation, polariton wave vector can be derived from offset ratio of the center point, and the ratio of polariton reflection and scattering rates at the edge is obtained from the ratio of the periodic and aperiodic patterns. This method can be widely used in the optical characterization of new vdW materials that are difficult to synthesize into large crystals, as well as nanophotonic integrated devices with unique boundaries.

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Impact of disorder on Dirac plasmon losses

Cited by 58 publications

References 28 publications

Highly confined low-loss plasmons in graphene–boron nitride heterostructures

Highly confined low-loss plasmons in graphene–boron nitride heterostructures

Real-Space Imaging of the Tailored Plasmons in Twisted Bilayer Graphene

A Multibeam Interference Model for Analyzing Complex Near‐Field Images of Polaritons in 2D van der Waals Microstructures

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