12,837 research outputs found
Mimicking Chiral Light-Matter Interaction
We demonstrate that electric-dipole scatterers can mimic chiral light-matter
interaction by generating far-field circular polarization upon scattering, even
though the optical chirality of the incident field as well as that of the
scattered light is zero. The presented effect originates from the fact that
electric-dipole scatterers respond selectively only to the incident electric
field, which eventually results in depolarization of the transmitted beam and
in generation of far-field circular polarization. To experimentally demonstrate
this effect we utilize a cylindrical vector beam with spiral polarization and a
spherical gold nanoparticle positioned on the optical axis -- the axis of
rotational symmetry of the system. Our experiment and a simple theoretical
model address the fundamentals of duality symmetry in optics and chiral
light-matter interactions, accentuating their richness and ubiquity yet in
highly symmetric configurations.Comment: 5 pages, 2 figure
Spin dynamics in relativistic light-matter interaction
Various spin effects are expected to become observable in light-matter
interaction at relativistic intensities. Relativistic quantum mechanics
equipped with a suitable relativistic spin operator forms the theoretical
foundation for describing these effects. Various proposals for relativistic
spin operators have been offered by different authors, which are presented in a
unified way. As a result of the operators' mathematical properties only the
Foldy-Wouthuysen operator and the Pryce operator qualify as possible proper
relativistic spin operators. The ground states of highly charged hydrogen-like
ions can be utilized to identify a legitimate relativistic spin operator
experimentally. Subsequently, the Foldy-Wothuysen spin operator is employed to
study electron-spin precession in high-intensity standing light waves with
elliptical polarization. For a correct theoretical description of the predicted
electron-spin precession relativistic effects due to the spin angular momentum
of the electromagnetic wave has to be taken into account even in the limit of
low intensities
Graphene plasmonics: A platform for strong light-matter interaction
Graphene plasmons provide a suitable alternative to noble-metal plasmons
because they exhibit much larger confinement and relatively long propagation
distances, with the advantage of being highly tunable via electrostatic gating.
We report strong light- matter interaction assisted by graphene plasmons, and
in particular, we predict unprecedented high decay rates of quantum emitters in
the proximity of a carbon sheet, large vacuum Rabi splitting and Purcell
factors, and extinction cross sections exceeding the geometrical area in
graphene ribbons and nanometer-sized disks. Our results provide the basis for
the emerging and potentially far-reaching field of graphene plasmonics,
offering an ideal platform for cavity quantum electrodynamics and supporting
the possibility of single-molecule, single-plasmon devices.Comment: 39 pages, 15 figure
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