34,975 research outputs found
Enantiospecific Detection of Chiral Nanosamples Using Photoinduced Force
We propose a high-resolution microscopy technique for enantiospecific detection of chiral samples down to sub-100-nm size based on force measurement. We delve into the differential photoinduced optical force ΔF exerted on an achiral probe in the vicinity of a chiral sample when left and right circularly polarized beams separately excite the sample-probe interactive system. We analytically prove that ΔF is entangled with the enantiomer type of the sample enabling enantiospecific detection of chiral inclusions. Moreover, we demonstrate that ΔF is linearly dependent on both the chiral response of the sample and the electric response of the tip and is inversely related to the quartic power of probe-sample distance. We provide physical insight into the transfer of optical activity from the chiral sample to the achiral tip based on a rigorous analytical approach. We support our theoretical achievements by several numerical examples highlighting the potential application of the derived analytic properties. Lastly, we demonstrate the sensitivity of our method to enantiospecify nanoscale chiral samples with chirality parameter on the order of 0.01 and discuss how the sensitivity of our proposed technique can be further improved
Higher Order Potential Expansion for the Continuous Limits of the Toda Hierarchy
A method for introducing the higher order terms in the potential expansion to
study the continuous limits of the Toda hierarchy is proposed in this paper.
The method ensures that the higher order terms are differential polynomials of
the lower ones and can be continued to be performed indefinitly. By introducing
the higher order terms, the fewer equations in the Toda hierarchy are needed in
the so-called recombination method to recover the KdV hierarchy. It is shown
that the Lax pairs, the Poisson tensors, and the Hamiltonians of the Toda
hierarchy tend towards the corresponding ones of the KdV hierarchy in
continuous limit.Comment: 20 pages, Latex, to be published in Journal of Physics
Deriving N-soliton solutions via constrained flows
The soliton equations can be factorized by two commuting x- and t-constrained
flows. We propose a method to derive N-soliton solutions of soliton equations
directly from the x- and t-constrained flows.Comment: 8 pages, AmsTex, no figures, to be published in Journal of Physics
Constructing N-soliton solution for the mKdV equation through constrained flows
Based on the factorization of soliton equations into two commuting integrable
x- and t-constrained flows, we derive N-soliton solutions for mKdV equation via
its x- and t-constrained flows. It shows that soliton solution for soliton
equations can be constructed directly from the constrained flows.Comment: 10 pages, Latex, to be published in "J. Phys. A: Math. Gen.
Semileptonic Decays to and in Bethe-Salpeter Method
Using the relativistic Bethe-Salpeter method, the electron energy spectrum
and the semileptonic decay widths of and
are calculated. We obtained large branching
ratios, and , which can be easily detected in the future
experiment.Comment: 3 pages, 3 figures
Classical Poisson structures and r-matrices from constrained flows
We construct the classical Poisson structure and -matrix for some finite
dimensional integrable Hamiltonian systems obtained by constraining the flows
of soliton equations in a certain way. This approach allows one to produce new
kinds of classical, dynamical Yang-Baxter structures. To illustrate the method
we present the -matrices associated with the constrained flows of the
Kaup-Newell, KdV, AKNS, WKI and TG hierarchies, all generated by a
2-dimensional eigenvalue problem. Some of the obtained -matrices depend only
on the spectral parameters, but others depend also on the dynamical variables.
For consistency they have to obey a classical Yang-Baxter-type equation,
possibly with dynamical extra terms.Comment: 16 pages in LaTe
Microwave-induced nonequilibrium temperature in a suspended carbon nanotube
Antenna-coupled suspended single carbon nanotubes exposed to 108 GHz
microwave radiation are shown to be selectively heated with respect to their
metal contacts. This leads to an increase in the conductance as well as to the
development of a power-dependent DC voltage. The increased conductance stems
from the temperature dependence of tunneling into a one-dimensional electron
system. The DC voltage is interpreted as a thermovoltage, due to the increased
temperature of the electron liquid compared to the equilibrium temperature in
the leads
B\"{a}cklund transformations for high-order constrained flows of the AKNS hierarchy: canonicity and spectrality property
New infinite number of one- and two-point B\"{a}cklund transformations (BTs)
with explicit expressions are constructed for the high-order constrained flows
of the AKNS hierarchy. It is shown that these BTs are canonical transformations
including B\"{a}cklund parameter and a spectrality property holds with
respect to and the 'conjugated' variable for which the point
belongs to the spectral curve. Also the formulas of m-times
repeated Darboux transformations for the high-order constrained flows of the
AKNS hierarchy are presented.Comment: 21 pages, Latex, to be published in J. Phys.
On the Numerical Dispersion of Electromagnetic Particle-In-Cell Code : Finite Grid Instability
The Particle-In-Cell (PIC) method is widely used in relativistic particle
beam and laser plasma modeling. However, the PIC method exhibits numerical
instabilities that can render unphysical simulation results or even destroy the
simulation. For electromagnetic relativistic beam and plasma modeling, the most
relevant numerical instabilities are the finite grid instability and the
numerical Cherenkov instability. We review the numerical dispersion relation of
the electromagnetic PIC algorithm to analyze the origin of these instabilities.
We rigorously derive the faithful 3D numerical dispersion of the PIC algorithm,
and then specialize to the Yee FDTD scheme. In particular, we account for the
manner in which the PIC algorithm updates and samples the fields and
distribution function. Temporal and spatial phase factors from solving
Maxwell's equations on the Yee grid with the leapfrog scheme are also
explicitly accounted for. Numerical solutions to the electrostatic-like modes
in the 1D dispersion relation for a cold drifting plasma are obtained for
parameters of interest. In the succeeding analysis, we investigate how the
finite grid instability arises from the interaction of the numerical 1D modes
admitted in the system and their aliases. The most significant interaction is
due critically to the correct represenation of the operators in the dispersion
relation. We obtain a simple analytic expression for the peak growth rate due
to this interaction.Comment: 25 pages, 6 figure
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