94,918 research outputs found
Some one dimensional solutions of nonlinear waves of a rate sensitive, elastoplastic material Technical report, 1 Sep. 1967 - 31 Aug. 1972
One dimensional solution of nonlinear waves of rate sensitive, elastoplastic materia
A Modified Optical Potential Approach to Low-energy Electron-helium Scattering
Optical potential approach to low energy electron- helium scatterin
Photon molecules in atomic gases trapped near photonic crystal waveguides
Realizing systems that support robust, controlled interactions between
individual photons is an exciting frontier of nonlinear optics. To this end,
one approach that has emerged recently is to leverage atomic interactions to
create strong and spatially non-local interactions between photons. In
particular, effective interactions have been successfully created via
interactions between atoms excited to Rydberg levels. Here, we investigate an
alternative approach, in which atomic interactions arise via their common
coupling to photonic crystal waveguides. This technique takes advantage of the
ability to separately tailor the strength and range of interactions via the
dispersion engineering of the structure itself, which can lead to qualitatively
new types of phenomena. As an example, we discuss the formation of correlated
transparency windows, in which photonic states of a certain number and shape
selectively propagate through the system. Through this technique, we show in
particular that one can create molecular-like potentials that lead to molecular
bound states of photon pairs
Synthesis of structural damping, volume I Final report
Hysteresis model for analyzing dynamic behavior of complex structure
Intensity dependences of the nonlinear optical excitation of plasmons in graphene
Recently, we demonstrated an all-optical coupling
scheme for plasmons, which takes advantage of the
intrinsic nonlinear optical response of graphene.
Frequency mixing using free-space, visible light
pulses generates surface plasmons in a planar
graphene sample, where the phase matching
condition can define both the wavevector and energy
of surface waves and intraband transitions. Here,
we also show that the plasmon generation process is
strongly intensity-dependent, with resonance features
washed out for absorbed pulse fluences greater than
0.1 J m−2. This implies a subtle interplay between the
nonlinear generation process and sample heating. We
discuss these effects in terms of a non-equilibrium
charge distribution using a two-temperature model.Peer ReviewedPostprint (author's final draft
Quantum pumping in graphene nanoribbons at resonant transmission
Adiabatic quantum charge pumping in graphene nanoribbon double barrier
structures with armchair and zigzag edges in the resonant transmission regime
is analyzed. Using recursive Green's function method we numerically calculate
the pumped charge for pumping contours encircling a resonance. We find that for
armchair ribbons the whole resonance line contributes to the pumping of a
single electron (ignoring double spin degeneracy) per cycle through the device.
The case of zigzag ribbons is more interesting due to zero-conductance
resonances. These resonances separate the whole resonance line into several
parts, each of which corresponds to the pumping of a single electron through
the device. Moreover, in contrast to armchair ribbons, one electron can be
pumped from the left lead to the right one or backwards. The current direction
depends on the particular part of the resonance line encircled by the pumping
contour.Comment: 6 pages, 5 figures. This is an author-created, un-copyedited version
of an article accepted for publication in EPL. IOP Publishing Ltd is not
responsible for any errors or omissions in this version of the manuscript or
any version derived from it. The definitive publisher authenticated version
is available online at 10.1209/0295-5075/92/4701
Spin states and persistent currents in a mesoscopic ring with an embedded magnetic impurity
Spin states and persistent currents are investigated theoretically in a
mesoscopic ring with an embedded magnetic ion under a uniform magnetic field
including the spin-orbit interactions. The magnetic impurity acts as a
spin-dependent -potential for electrons and results in gaps in the
energy spectrum, consequently suppresses the oscillation of the persistent
currents. The competition between the Zeeman splittings and the -
exchange interaction leads to a transition of the electron ground state in the
ring. The interplay between the periodic potential induced by the Rashba and
Dresselhaus spin-orbit interactions and the -potential induced by the
magnetic impurity leads to significant variation in the energy spectrum, charge
density distribution, and persistent currents of electrons in the ring.Comment: 8 pages, 11 figure
- …