Date:
Wed, 13/01/201614:00-15:30
Location:
Danciger B building, Seminar room
Lecturer: Dr. Ido Kaminer
Affiliation: Technion - Israel Institute of Technology
Abstract:
Rapid technological progress continues to provide
new ways of manipulating and confining light on
the nanoscale. The seminar will discuss how 2D
materials (such as graphene) create novel states of
light that facilitate new effects of light-matter
interaction and give new insight into old and
fundamental problems in physics.
We revisit electron-photon scattering theories such
as the Compton/Thomson effect, and develop a
new electron-plasmon scattering theory. We use
this scattering theory to propose a highly
directional, tunable and monochromatic radiation
source based on free electrons interacting with
graphene plasmons. Graphene plasmons show
strong confinement of light, 200-300 times more
than light of the same frequency in vacuum. This
enables the generation of high frequency radiation
from relatively low energy electrons, bypassing
the need for lengthy acceleration of the electrons.
For instance, highly-directional 20 keV photons
could be generated in a table-top design using
electrons from conventional radiofrequency (RF)
electron guns.
A related property of plasmons is their potentially
very slow phase velocity, which for plasmons in
2D conductors can be several hundred times
slower than the speed of light. We show how this
property creates the scenario where the velocity of
light can become comparable for the first time to
that of charge carriers flowing through graphene.
Then, the interaction between the charge carriers
and the plasmons presents a highly efficient,
tunable, and ultrafast conversion mechanism from
electrical signal to plasmonic excitation. This
happens since the velocity of the charge carriers
breaks the “light barrier”, leading to Čerenkov
radiation of plasmons in 2D. Quantum mechanical
considerations in the graphene Čerenkov effect
reveal new features that the usual classical
treatment does not predict.
Altogether, the seminar will touch topics in light
matter interaction, condensed matter physics,
photonics, as well as in electron beam and
accelerator physics.
Affiliation: Technion - Israel Institute of Technology
Abstract:
Rapid technological progress continues to provide
new ways of manipulating and confining light on
the nanoscale. The seminar will discuss how 2D
materials (such as graphene) create novel states of
light that facilitate new effects of light-matter
interaction and give new insight into old and
fundamental problems in physics.
We revisit electron-photon scattering theories such
as the Compton/Thomson effect, and develop a
new electron-plasmon scattering theory. We use
this scattering theory to propose a highly
directional, tunable and monochromatic radiation
source based on free electrons interacting with
graphene plasmons. Graphene plasmons show
strong confinement of light, 200-300 times more
than light of the same frequency in vacuum. This
enables the generation of high frequency radiation
from relatively low energy electrons, bypassing
the need for lengthy acceleration of the electrons.
For instance, highly-directional 20 keV photons
could be generated in a table-top design using
electrons from conventional radiofrequency (RF)
electron guns.
A related property of plasmons is their potentially
very slow phase velocity, which for plasmons in
2D conductors can be several hundred times
slower than the speed of light. We show how this
property creates the scenario where the velocity of
light can become comparable for the first time to
that of charge carriers flowing through graphene.
Then, the interaction between the charge carriers
and the plasmons presents a highly efficient,
tunable, and ultrafast conversion mechanism from
electrical signal to plasmonic excitation. This
happens since the velocity of the charge carriers
breaks the “light barrier”, leading to Čerenkov
radiation of plasmons in 2D. Quantum mechanical
considerations in the graphene Čerenkov effect
reveal new features that the usual classical
treatment does not predict.
Altogether, the seminar will touch topics in light
matter interaction, condensed matter physics,
photonics, as well as in electron beam and
accelerator physics.