6 research outputs found
Supplementary document for Deeply Subwavelength Integrated Excitonic van der Waals Nanophotonics - 6601887.pdf
supplemental informatio
Dipole-matter interactions governed by the asymmetry of Maxwell equations
Directionally molding the near-field and far-field radiation lies at the heart of nanophotonics and is crucial for applications such as on-chip information processing and chiral quantum networks. The most fundamental model for radiating structures is a dipolar source located inside a homogeneous matter. However, the influence of matter on the directionality of dipolar radiation is oftentimes overlooked, especially for the near-field radiation. We show that the dipole-matter interaction is intrinsically asymmetric and does not fulfill the duality principle, originating from the inherent asymmetry of Maxwell equations, i.e., electric charge and current are ubiquitous but their magnetic counterparts are non-existent to elusive. Moreover, we find that the asymmetric dipole-matter interaction could offer an enticing route to reshape the directionality of not only the near-field radiation but also the far-field radiation. As an example, both the near-field and far-field radiation directionality of Huygens dipole (located close to a dielectric-metal interface) would be reversed, if the dipolar position is changed from the dielectric region to the metal region
Quantum Control of Graphene Plasmon Excitation and Propagation at Heaviside Potential Steps
Quantum
mechanical effects of single particles can affect the collective
plasmon behaviors substantially. In this work, the quantum control
of plasmon excitation and propagation in graphene is demonstrated
by adopting the variable quantum transmission of carriers at Heaviside
potential steps as a tuning knob. First, the plasmon reflection is
revealed to be tunable within a broad range by varying the ratio Îł
between the carrier energy and potential height, which originates
from the quantum mechanical effect of carrier propagation at potential
steps. Moreover, the plasmon excitation by free-space photos can be
regulated from fully suppressed to fully launched in graphene potential
wells also through adjusting Îł, which defines the degrees of
the carrier confinement in the potential wells. These discovered quantum
plasmon effects offer a unified quantum-mechanical solution toward
ultimate control of both plasmon launching and propagating, which
are indispensable processes in building plasmon circuitry
Faraday Rotation Due to Surface States in the Topological Insulator (Bi<sub>1–<i>x</i></sub>Sb<sub><i>x</i></sub>)<sub>2</sub>Te<sub>3</sub>
Using
magneto-infrared spectroscopy, we have explored the charge dynamics
of (Bi,Sb)<sub>2</sub>Te<sub>3</sub> thin films on InP substrates.
From the magneto-transmission data we extracted three distinct cyclotron
resonance (CR) energies that are all apparent in the broad band Faraday
rotation (FR) spectra. This comprehensive FR-CR data set has allowed
us to isolate the response of the bulk states from the intrinsic surface
states associated with both the top and bottom surfaces of the film.
The FR data uncovered that electron- and hole-type Dirac Fermions
reside on opposite surfaces of our films, which paves the way for
observing many exotic quantum phenomena in topological insulators
Untersuchungen ueber die Auswirkungen einseitiger Kastration und abdominaler Hodenreposition auf inkretorische und exkretorische Funktionen der skrotalen Keimdruese beim Hund; Beitrag im Rahmen der Arbeitsgruppe "Fortpflanzung und Besamung" an der Tieraerztlichen Hochschule Hannover
Available from: Zentralstelle fuer Agrardokumentation und -information (ZADI), Villichgasse 17, D-53177 Bonn / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Efficiency of Launching Highly Confined Polaritons by Infrared Light Incident on a Hyperbolic Material
We
investigated phonon–polaritons in hexagonal boron nitridea
naturally hyperbolic van der Waals materialî—¸by means of the
scattering-type scanning near-field optical microscopy. Real-space
nanoimages we have obtained detail how the polaritons are launched
when the light incident on a thin hexagonal boron nitride slab is
scattered by various intrinsic and extrinsic inhomogeneities, including
sample edges, metallic nanodisks deposited on its top surface, random
defects, and surface impurities. The scanned tip of the near-field
microscope is itself a polariton launcher whose efficiency proves
to be superior to all the other types of polariton launchers we studied.
Our work may inform future development of polaritonic nanodevices
as well as fundamental studies of collective modes in van der Waals
materials